Taylor Swift has some really good, catchy songs that I enjoy hearing.

I think the dislike of vegans mostly stems from the militant wing of that movement claiming moral superiority over anyone who has the gall to disagree with them, and their movement relies way too much on emotion and shock porn/"omg it's a dead animal!!!!" than environmental reasons, which I believe are way more persuasive.  

I have zero issues with vegans in general as long as they mind their own business.  But, as an aside, I've experienced several instances in my life where vegans get exasperated and complain that they have nothing to eat at someone else's house, but would never extend the courtesy of providing non-vegan options for non-vegan guests if the shoe was on the other foot.  There is an expectation in general that I've seen in several vegans (definitely not all) that they expect to be catered to by other people who do not conform to that diet, and I think common courtesy should go both ways in this aspect.

Still, at the end of the day, no one likes being preached to, and that's probably why vegetarians are left alone for the most part.