Repaying student loans makes a lot of people a little richer. The current initiative makes a few people a lot richer. If you ask some people, the former is a very communist/socialist way of thinking (bad), while the latter is pure, unadulterated capitalism (good).
You can make the same argument about going to the moon. Why bother when so many problems could be solved on earth.
One of the more destructive situations in capitalism is the fact that (financially) helping the many will increase inflation and lead to more problems.
When a few people get really rich it kind of slips through the gaps, the broader system isn't impacted too much. When most people get a little rich they spend that money and prices go up. Said differently, wealth is all relative so when most people get a little more rich their comparative wealth didn't really change.
That and a lot of people do not have the means to convince current power centers ( unless they were to organize, which they either don't, can't or are dissuaded from ) to do their bidding, while few rich ones do. And so the old saying 'rich become richer' becomes a self-fulfilling prophecy.