Is this serious? Vegans/vegetarians are among the most obnoxious people on the planet. I have yet to meet one who has a live-and-let-live mentality. They seem to be on a mission to "convert" the whole planet.
And you analogy with slavery is weak at best. You would had Inuits die of starvation? Humans condemned to back-breaking earth tilling?
RE: Do vegans 'force' their opinions on others?