Is there data to suggest that? Public schools are generally very good about providing a variety of extra-curricular activities to keep students focused upon athletic and scholarly activities outside the classroom if the student is willing to participate. Contrast those tax funded and faculty lead activities to private tutors and rigorous SAT practice that is almost exclusively limited to families with the personal financies to afford such.
> It largely feels like an excuse to lower the competitive bar to manage the demographics
I can certainly empathize with that. Wealthy households had an advantage with private tutors and timely dedicated/forced test preparation activities. Now that advantage has evaporated so that wealthy students are now less exclusively advantaged, or in other words the bar of entry has lowered to wider availability.