It's pretty clear that Robinhood users are incredibly leveraged right now on these transactions. Someone in finance probably gave their team a "Come to Bernanke moment" and pointed out that when the bubble pops they will be eating a huge load of crap where they are on the hook for a bunch of teenagers' margin calls.
It's crappy all around, but the ball was in their court for giving so many people the ability to trade on the margin.