So here you are accusing people of wanting to intentionally keep low SES, non-suburban kids out of UC’s. This is a wildly offensive accusation. I have not seen this opinion voiced in any of the comments.
But now you move the goalposts. Yes, some of the posts, including mine, absolutely think that one UC school in particular that has itself identified a problem - UCSD - is admitting “supposedly less qualified students at the expense of supposedly more qualified students.” This is very different than saying UC schools should keep out low SES kids. Believe me, there are plenty of rich privileged kids with poor test scores at UCSD who are also under-prepared for UCSD classes. They too should not be taking the spots of better prepared applicants. And, in fact, the Dartmouth report suggests that low SES kids actually benefit when competitive schools require test scores because they can better assess those students’ achievements in context.