Andrew Yang had a great reason for NOT signing the progressive pledge and why he didn't support free college for everyone.

His reasoning was 2 fold.

1) His UBI would help college students drastically and be a stimulus for college age kids.

2) His words, "Only 33% of people go to college" IIRC he also stated that this would only help 1/3 the population and that we need to promote alternatives to college instead.

I think there are two more issues with college. Some jobs require college degrees but really shouldn't (some not all). Some degrees offer little to no economic benefit to the student but are sold to the student at a premium.

There are some really great reasons why we need to resolve current student debt, but I think we need to overhaul how we view high school / college for everyone rather than for 1/3 of the population.