Some people like to be choked while in the act and some people like to do the choking. All personal preference.

I personally like to be bit.... (not to draw blood lol) While the next whore likes to be choked... and another might like to lick arm pits. I dunno... If its something done safely and both people enjoy it. I see nada wrong with it.

I have had a few hands around my next in scenes... but never once passed out or was asked to do it....

I dont think its as common as your making it out to be (Girls passing out on set from being choked)