[kuschku]

But how does putting people with worse grades in college help?

It doesn't fix the actual issue: access to quality primary and secondary education.

If a person going to a school with mostly minorities and underpaid staff never heard of complex numbers, then their math study won't be successful, no matter if they need a 3.5 or 3.0 GPA to attend.

Sure, attendance rate goes up, but the outcome is the same.

You need to target the roots of the issue, not the outcome.