I think the argument is that someone whose parents are richer can afford to boost their kids' scores through tutoring, prep classes etc. So, if there are two identical kids, one whose parents have more resources will come out ahead.

I think one needs to be careful of survivorship bias here -- "the system worked for me, so it is fine".

The issue with banning SAT/ACTs, etc. is that is the system they're using in its place with actually better?

However, many well off parents will feel like they worked hard to move up, and provide their kids with best educational opportunities... but now the rules are changing. It is definitely a hard problem to try to equalize for wealth and at the same time not overly penalizing somewhat wealthy parents that also care about kids' education.