its turned into an exclusive evangelicals movement that is bullying its message across rather than trying to achieve organic growth by providing education and a superior product that consumers could switch over too easily.
That's funny, because about 90% of the vegans that I know don't ever talk about it, except through the food they are preparing and sharing with people. The "bullying" you are referring to is generally from those who are new to a realization, and we see it with anarchism, atheism, veganism, and every other group where folks have realized they were lied to and tricked for a long time.
This seems to be a balance of self-judgement for what they only recently stopped doing/believing, frustration with people not listening, and often a bit of a superiority complex.