i agree with you to an extent, but i think some context is missing. questbridge is for low-income students, and my guess is that a low-income student could not afford the risk correlated going to a testing center, and could not drive extreme lengths to take it. thus, most questbridge applicants probably did not have scores to begin with. so, it's not really the case that "oh people without scores can get in everywhere," because colleges do have to accept a certain amount of questbridge applicants no matter what (they have a certain amount / yield they expect) - if the only applicants they're offered have no scores, they still do need to let some in.

but also keep in mind that questbridge applicants are the first people schools make decisions on - they aren't necessarily competing against normal ED applicants with great scores, they're competing among themselves, who have no scores.