And that's the main reason I avoid public group rides like the plague - the safe, experienced, and highly skilled riders are but put at risk by the inexperienced Dunning Kruger crowd. ANY group ride is only as safe as it's weakest link - if wannabe Rossi on the Busa riding with an M1 decides he wants to do 200 on the straights but then has zero ability to actually slow down and runs into the back of me, well, I'm still going to likely end up in the hospital along side him through zero fault of my own. Likewise the guy who can't corner worth **** - if he drops his bike because he "forgot to steer" in a corner riding beyond his skills and then 20 other bikes behind him domino into the wreck and I end up part of the mess, well again, there I am potentially in the hospital through zero fault of my own.
I went on one huge (300+ bikes) public group ride last year because it was for a charitable situation that I have very direct ties to. Sure enough there was a complement of goons and idiots putting everyone else at risk.
I do a lot of group riding but with people I know, with expected standards of the organization, and with basic competency requirements. If you have any issue with any of those requirements you need to do some more solo riding or experience building with a friend or two versus riding in a bigger group of 10-20 bikes.