What is maximalism & history explained.
Bitcoin (or any other) maximalism is a belief that the world is best served by optimising along a certain axis (for instance, the entire world adopting Bitcoin) to the exclusion of other tradeoffs that might be available (in our example, usage of any other fiat or cryptocurrency).
History of maximalism
In the early days of cryptocurrency, Bitcoin comprised 99%+ of the total market capitalisation & anyone involved in cryptocurrency was guaranteed to be heavily invested in, aware of & involved with the Bitcoin community. Maximalism was the widespread belief in the Bitcoin community at that time that Bitcoin would become the global reserve currency & replace all alternatives. This was premised on Bitcoin's clearly superior monetary properties in combination with the belief in its superior network effect and the assumption that any valuable innovations or breakthroughs pioneered in the tiny, fringe alternatives would naturally be absorbed into the forward thinking Bitcoin project. There was no distaste for alternatives, simply all the action was going on in Bitcoin so it was obvious to be involved & there was no need to be protectionist or concerned about fragility in such a clearly innovative & forward thinking project.
As the scene diversified into a broader variety of projects, triggered largely by the division & chaos of the Blocksize War, the intensity of Bitcoin maximalism ramped up as both sides of the civil war believed they were in an all-or-nothing struggle for a once-in-civilisation shot at ending the hegemony of fiat currency & central banking. Non-maximalists migrated into other projects, while maximalists stayed to fight it out due to their higher passion & conviction. The "small block" side came out victors, winning the BTC ticker and forcing big blockers into a chainsplit & BCH ticker/branding.
The polarisation of the debate & multitude of compromise failures had a secondary effect of convincing the winning small block/BTC maximalists that conservative protocol development was essential. They began to believe that ideas proposed from people outside their circles were "attacks" against Bitcoin & must be fought & resisted. Thus maximalism had its meaning inverted from proactive interest & investigation of outside innovations for inclusion into Bitcoin to be the exact opposite - an aggressive default resistance to changing Bitcoin in any way, especially regarding ideas that began outside BTC maximalist circles.
BTC "toxic" maximalism
Well-known maximalist & prolific Twitter poster "Mr Hodl" exemplifying the spirit of "toxic maximalism".
After the split, BTC supporters took away from the conflict a belief that they must actively seek out & destroy "harmful" influence in the BTC ecosystem, such as the expelled big block ""infiltrators"". The original pro-inclusivity maximalism morphed into so-called "toxic maximalism", which many prominent BTC community figures wore as a badge of honour. They believe that Bitcoin is the only "pure" coin, that all alternatives are scams, and it is their duty to protect Bitcoin & new adopters by aggressively decrying, censoring, spreading propaganda or otherwise attacking those projects or anyone associated with them. From their perspective, they are acting as the "immune system" of Bitcoin by repelling unwanted outside influence. In practice, they are just acting immature, obnoxious & close-minded.
Podcast segmenting explaining why the BCH community should be maximalist & the correct strategy for building network effect.
Bitcoin Cash retained the original spirit of maximalism, although unfortunately tarred & confused as a label by the BTC perversion. The Bitcoin Cash Podcast is proudly a "BCH maximalist" endeavour, although as per the original maximalism that means no rancor against other free-market cryptocurrency competitors. Many advocates or maximalists of other coins have appeared on The Bitcoin Cash Podcast in the past & will continue to in the future. Alternatives can & should flourish & any learnings or ideas the BCH community can adopt from their success should be rationally considered.
Many other projects in the BCH space similar adopt an approach of being BCH exclusive maximalists - by the BCH community, for the BCH community. Integrations with other coins are often set aside in favour of additional development time on BCH features or collaboration with other BCH maximalists. This is not about disliking alternatives, but rather a pragmatic lesson that multicoin projects tend to have divided focus or loyalties. At the same time, BCH projects tend to be the most resilient & build the fastest network effect by specialising within that niche. Bitcoin Cash maximalists by and large take a very keen interest in observing other crypto ecosystems to stay abreast of the latest in the industry, even if they do not regularly collaborate with those influences directly.
On the importance of maximalism
It is very important for a coin to have maximalists. It is a huge benefit that BCH is able to have a non-toxic maximalist culture. Even the BTC laser eyes are in many respects a positive for BTC despite their less-than-ideal toxicity.
If cryptocurrencies were sports teams, maximalists would be the star players. Don't have enough & you simply can't compete in the big leagues against teams that do.
Maximalists are by definition the people most committed to a given coin. Those overwhelmingly passionate people are the ones who build, run & maintain most of the essential infrastructure in that community. Node software, dedicated wallets, community news channels (such as The BCH Podcast), dedicated meetup groups & more are all started & maintained at enormous effort by maximalists. These essential, costly, coin specific projects do not last long without maximalist passion & committment. Every coin gets listed on exchanges, occasional articles on news aggregator sites & so on - especially if it is one of the larger projects - but the thing that drives a coin in the first place is the combined effort of its maximalists.
Therefore the resilience & potential growth/improvement of a cryptocurrency can be approximated by the strength of maximalist culture in the coin multiplied by how many maximalists there are (the more the better). Coins with large amounts of maximalism should be considered most seriously by people involved in the cryptocurrency community.
The most maximalist coins in cryptocurrency are:
Maximalism in other contexts
Over time, the idea of "maxis" spread as a label for supporters of other coins. For instance "Ethereum maxis" believe strongly in Ethereum & its superiority to competing alternatives, same for "Monero maxis" or "Litecoin maxis".
This idea of being ideologically, culturally, economically and/or philosophically bought into one particular set of tradeoffs then evolved to even more widespread use - for instance some cryptocurrency users who do not align strongly to a particular coin may instead describe themselves as "freedom maximalists" or "privacy maximalists", valuing those attributes above other options in their choice of currency, occupation or lifestyle.