Well, in the 20ish years I've been vegan I've never met anyone who thinks all vegans are annoying, or preachy.
But there are, of course, people unimaginative enough to make (and even believe) sweeping generalisations about groups of people - based on such flimsy evidence as the appearance, diets, beliefs, interests, gender etc of a particular group.
And though I've never come across one in real life, there are contributors to this forum who make absurd generalisations about vegans.
One regular repeatedly states that all vegans are ignorant, aggressive, rude, over-emotional, uptight and edgy - among other derogatory adjectives.
Another regularly says all vegans (yes, ALL) are liars; example - 'as we all know, vegans lie'.
These are unimaginative people with little life experience and an axe to grind, in my opinion.
In the case of your friends - well, you say that these comments are made 'whenever I talk to people that eat meat'. So although you don't feel you come across as preachy, this suggests that you frequently bring up the subject of your veganism, which might be what annoys them