Don't think the colleges are the culprits. Their goal is to increase matriculation, get more students, more research grant money, etc. They are just trying to do more of what they have already done.
Arguably, the real culprits are the businesses that require college degrees, i.e., that require said "rubber stamp". A person who spends 1 year taking a $15k set of trade-courses will likely accept less pay than someone who spent 4 years and $150k. However, most businesses will choose the 4 year college grad every time.