I think BPD is very misunderstood, thus people with BPD are misunderstood and I think because a lot of the presenting issues that people with it have, some people place a negative stigma on it, especially because they frequently present to the ed with si and sh. 
And while yes it is just a label, proper diagnosis are important because treatment is dependent upon a correct diagnosis. Not sure if it's the way with BPD, but having a correct diagnosis for an eating disorder enables far more treatment options than just a mental health plan. 
I've said it before and I'll say it again, there needs to be much education in the health system.. and general population around mental health issues. People don't understand. People judge. People stigmatise. It's engrained in society that if your not like everyone else, that if your not 'normal', then there is something wrong and that opens the flood gates  for judgment, criticism and I think in ways confirms to someone already struggling that there indeed is something incredibly wrong with them. It adds another layer to an already complicated situation. 
Rambling sorry. I have an BPD diagnosis also.