Bbwomg:
I notice that mutual gaining in general is very divisive, some people love it, some are open to it, for others its a flatout no, whats everyones opinion on the matter?
I wouldn't call it divisive, it's merely a case of compatibility and open, honest communication.
If you're into mutual gaining and your partner has very clearly stated that they aren't then it's either off the table or an indication that they aren't the right person for you. Pressuring someone into doing something they don't want to just because it makes you hot isn't okay, and using sneaky tactics to trick or sabotage a partner into gaining with you is down right wrong.
If you're both into mutal gaining and you've talked about it and decided to explore it, awesome. Hopefully it's something both enjoy and have fun with. But if one of you decide you've had enough, or is not enjoying it as much as you thought you would and want to stop, that needs to be respected.
I suspect a lot of the "divisiveness" you mentioned is coming from people that have had someone try to trick or oressure them into mutal gaining when they weren't into it or weren't ready to explore it. Again, open, honest communication is key.