This is definitely true! I do think that a lot of the stereotype about "obnoxious vegan" is something invented by people who eat to make themselves a little more comfortable with the moral tradeoffs they are making.

I say this as someone who has met lots of vegans in my life (and also is not one). The vast majority are not very pushy at all. The pushy ones exist, but seem to be much more common in the collective imagination of meat-eaters.