Just to give you my opinion..
There are a lot of cam girls that would never ever consider doing hardcore porn, maybe some girl - girl action but that is it ..and I can understand that ..Being on cam is a lot less intrusive than being on a porn set ...
Also a lot of girls do have boyfriends, husbands and I can imagine that those would not be thrilled seeing their wife or GF being gang banged in a shoot ( just to put it a bit over the top)....
For me personally: Yes I do porn , including girls, guys and GB's ... I don't care what others think ...I love being on cam and when you do well on cam , believe me it is better paid than any porn.....Even top porn girls at Vivid/Digital Playground make less in their contracts (excluding the lucrative side jobs) than top cam girls...but I love doing porn as well...
I can understand that cam girls stay away from it ..Doing porn puts you and your name even more in the public eye and any sense of privacy will be gone soon... My few cents on the topic