Perhaps you should reread what I wrote.
Stock buybacks aren't "hoarding". Sitting on piles of cash and note reinvesting it/distributing it as dividends/buying back shares to increase shareholder equity *is* generally hoarding, unless there is some plan for the use of the Scrooge McDuck -like piles.
Companies that sit on hoards of cash without abelievable plan for its use seem to eventually get targeted by other folks who swoop in, do a takeover, cut up the company into bits, and turn the capital to more efficient uses. This is of course not an instantaneous process, so you almost always can point at some poster-child corporation with tons of loot cluttering up its hallways.