It's no such thing. As a shareholder I am happy for companies to buy back shares and thereby increase the value of the remaining shares.
I don't think that's what we're seeing in the vast majority of cases though. I think what we're seeing is managers personally enriching themselves by taking on corporate debt and doing so in a very tax-advantaged way. Keep in mind they're not buying the stock they own in the first place, they're being given it via stock options at crazy discounts.
...is your salary received from the company at a "crazy discount"? the equity is part of the agreed upon compensation for the manager's work.
this is easily the most absurd statement on this entire page.