It most certainly does happen. Most annoying is when it is with a coworker or family member - you go out to a restaurant or otherwise eat together and the other person ends up frustrated that you won't eat meat. Last time my mother visited we went to a Chinese buffet restaurant and she harassed me about it continually. Last time I visited my grandmother she was nearly in tears because I didn't want to eat some things she made with meat (she knew I was vegan and considers herself to be vegetarian, but will do things like making a soup using sausage "just for the flavor", then removes the meat pieces and feeds them to her dog and considers the remaining soup to be "vegetarian"...). People at my workplace randomly give me crap about it all the time, despite me never trying to push my agenda on them or even disclosing my preferences unless asked.
That said, I have seen a bigger presence of dogmatic vegans which I feel do more harm than good. By far the most extreme example of that I have ever seen is this:
https://www.youtube.com/watch?v=EYPAxEcZeuw
I agree, but sometimes it is a self-inflicted term. See above in this thread for an example of someone using the term "meatitarian" for referring to themselves - I think sometimes omnivores choose to use a word like "carnivore" or "meatitarian" to make it clear that they are not just non-vegetarian, but are actively against it. That said even a person who is staunchly anti-vegetarian in their own meals can be very respectful and courteous to those of a different outlook.
What is key is for everyone to realize they can only really control their own actions, and to be respectful to others who make different decisions for themselves. It's fine to respectfully discuss, explain, and even encourage one's own stance; it's not fine to get overly upset and condemn others for choosing something different. Food choice seems to be a very touchy subject, and few are willing to up and change their beliefs and habits overnight.