To add on: the scenario described is a real one but I think a lot of caveats should be added, cuz even in your scenario ~1/2 of the people are making it through and will join the partnership and be able to make nearly seven figures. If you told a group of residents that if they signed with this hypothetical group out of training they would have a 50% chance of making $1m per year, i think a fair number of them would try.
I've worked in two big groups that made high 6 figures (approaching 7 several years). Both of which formerly had long partner tracts and large buy-ins.
There were people in both who didn't make it to partner. In almost every case, the people in question were told that their speed was concerning at the 6-12mo period and that they needed to speed up before they'd be considered for partnership. Some of those people left immediately, knowing they either couldn't or didn't want to. Many stayed cuz the upside of partnership was worth the attempt but ultimately didn't progress fast enough to be offered partnership, but as you said were either offered continued associate status/employee status. A few actually were able to make changes to the partnership's expectations and were happily accepted into the partnership without reservations.
In any event, my take home point is that if you're a trainee/junior rad and you hear that XYZ group makes high 6's/low 7's but that a number of associates don't make it.... it's not necessarily because the group is predatory/bottom feeding. High 6's/low 7's is 90th plus percentile compensation. You should expect to produce 90th plus percentile production. Many people cannot and/or do not want to do that. Understand there's no free lunch. If you weren't a devourer of lists in residency you prolly won't do well in a high volume, high compensation group.
I suppose it depends on how transparent you are about the failures of desired associates to attain partnership status with applicants. But most groups don't want to share who was an associate and failed to get partner, and how many there were. So frankly, as reasonable as you seem to make it sound, my opinion is such groups rationalize their approach as egalitarian, while simultaneously fooling naive new grads by obfuscation and misleading. Let's say a new grad is 1.5 years in, the group doesn't like their quality / quantity... do you tell them immediately that they won't make partnership status? You wait another year, they haven't changed... do you tell them now?
Of course not. You let them keep chugging, subsidizing your income for you, and then at the four year mark you break the tough news. They bounce, new associate, rinse and repeat.
A polished turd is still a turd. If you're ripping 30-50% off the top of a young rad with statistically unlikely promises of a golden future, you are no different than the PE guys. Especially because 7 figures is such a high income (significantly above 90th percentile), I don't care how fast you read or how good your contracts are,
someone is subsidizing you. Either the hospital, or the new grad labor.
Maybe I'm just a jaded cynic, but after seeing how the majority of practices treated new grads during the hellpit from '08-'15, I really don't have faith in rad practice leadership whatsoever in their ability to look out for
anyone's interest but their own. Idgaf how they rationalize it.