I think you cannot infer too much from a random Reddit discussion thread. Any sane person understand that it's irrational, both from a technological and financial perspective, to be "loyal" to something.
Bitcoin maximalism is a rational wolrdview, with real arguments, not some juvenile fanboy stuff "my blockchain is better than yours", imho.
It's rational in the sense that people like to make money and that is rational. But it's also unwise because it damages the ecosystem to benefit quicker profits for fewer people.
The ecosystem is more resilient, robust, and adaptive when multiple crypto technologies are allowed to evolve compete for market fitness. The most fit technologies will reproduce and their source code will spread.
It's more important that our ecosystem evolve the best technologies than for a few people to pocket some millions and disrupt the evolutionary trajectory. If we get this right we all win big as we'll have more variation in the DACs, which can allow DACs to attract more people, which can grow the overall network effect, and which over time can benefit our favored chains as well.
Vitalik is correct and I can site some research which shows that variation is necessary for the evolutionary process to work. If you for example look at an interactive genetic algorithm or interactive evolutionary computation network and compare the decentralized application/DAC ecosystem then you can actually see that there is a Darwinian process at work. The process benefits from diversity in the form of mutations to the code base and underlying technology because it is through that process that the evolutionary algorithmic process evolves to meet the wants and needs of the human participants.
Bitcoin isn't going to meet the needs of everyone on earth. It barely meets the needs of most libertarians, most tech oriented libertarians, and even if they were to implement side chains it's not going to convince people who aren't politically aligned with the currently forming blockchain ideology. Some people think Bitcoin is concentrating far too much into the hands of far too few and the current SHA-256 mining algorithm centralizes power.
So you have millions of people who might for equally rational reasons determine that Bitcoin is "unfit" for their needs. They might choose a blockchain which is "fit" for their needs and this is the process of artificial selection which should evolve mutually beneficial ecosystem. In my opinion we have to think bigger than just how we can get rich as quickly as possible and think seriously about how these technologies could alter the society of humans who interact with it.