The one good thing I should mention about vegans is that most really want to improve the world, whether I believe that the method is good to achieve the goal is irrelevant to the intention.
The problem with thinking on terms of suffering is that vegans tend to equate how sentient and intelligent these animals are by their ability to empathize with them. I don't meassure pain by comparing that pain to my own because I understand different creatures process things differently and that doesn't make their experiences more or less valuable.
I could look at an oyster, for example, and not be able to compare to any other animal I have seen, much less myself. This creature doesn't move like other creatures and can't scream in pain in a way I can relate to my own screaming when I am in pain. Because of this most people will tell you that they prefer to eat an oyster than say a rabbit, regardless of how their consumption of these creatures may affect the enviroment.
For many years, since I recognize that we eat too much meat and that has negative effects not only on us but everything else, I tried reaching out to vegans to join forces in trying to create enough awareness for people to eat less meat. But soon I discovered that eating less meat is not enough, I discovered that eating any meat that they consider sentient would make me a beast in their eyes, and I was simply not in the mood to be looked down upon which drove me to discard that movement entirely.
This doesn't mean that I don't see value in eating less meat, it just means I don't see enough value to spend my time not only dealing with people who think I am a monster, but dealing with people who could potentially drive others to do the exact thing they are trying to prevent.
RE: Speak Up for Animals: you don’t need a dietary adjustment; you need an attitude adjustment