I honestly think many vegetarians/vegans, etc are just too uptight. Worry too much about things they honestly can't control, which leads down the path of an ultimate unhealthy end to one's life.
But that really has nothing to do with deciding if a vegetarian lifestyle is healthier than the alternative, which I believe it is.
It just speaks to stress being the ultimate killer, and trumping even the healthiest dietary habits.
You can't communicate your way out of something you behaved yourself into