Nobody is forcing you to do anything. If you want to fly under the protections of 336 then you need to comply with 336 including flying under the safety programming of a CBO

Otherwise you get certified and fly under 107

At this time there's only one CBO and that CBO says you need to be a member to be under their programming.

Personally I support the AMA because they are the reason there is a 336 and an option to fly that doesn't require a difficult certification exam.

Note that other users here disagree with that interpretation, thats fine for him but not accurate as I read the law