People consider vegans on Lemmy as too preachy. Even in vegan communities here, mods have to remove soooo many inappropriate comments (I read a few of these and they keep getting removed for good reasons). Comments that suggest going vegan on posts about animal abuse are downvoted.
At the same time, whenever there is something about Windows or Chromium based browsers, people here are doing exactly the same. “Just use Linux/Firefox/whatever”.
However there’s a huge moral charge on veganism that isn’t there on FOSS stuff unless a person’s very eagerly drawing connections to AI apocalypse or something like that