What do you mean scummy though? Having been part of a church hopping family in the past most church hopping happens to get away from the stuff you probably call "scummy." Like we would leave churches cus the pastor would get up and preach at us about how evil our saturday morning cartoons were. I literally had a 4th grade sunday school teacher tell me that watching captain planet was wrong because it worshiped the earth instead of god or some nonsense and was created by ted turner who is an atheist or something. My parents kind of had a field day with that and we switched. It happened a lot actually, us switching from churches that were too preachy and not accepting into ones that were. That seems more the norm than a bunch of hardliners who you describe as scummy banding together to form their own church.
Any of them that preach hate or intolerance or are just in it for what they can get out of it, not what the congregation gets out of it.