Messing in what way? They are buying from willing sellers at the market price, using funds that are announced well before hand in public government filings (Form 10-Q and 8K) are to be used to buyback shares
Sure, bids hitting the orderbook theoretically keeps a stock price higher than the counterfactual where the bids did not exist, but it's simply urban myth that failing companies can keep their stock price high over the long term with buybacks. The math doesn't pencil out.
Are you an executive who will gain millions by doing it, and you are doing it with company money that your have corporate control over? Then yep.
Maybe executives shouldn't have stock. Then it wouldn't be manipulation.
But they do. That is their main compensation people like to point (the CEO isn't really getting paid those millions, it's stocks). So the CEO is paid in a way that encourage the CEO to commit DIRECT stock manipulation.
Sure, bids hitting the orderbook theoretically keeps a stock price higher than the counterfactual where the bids did not exist, but it's simply urban myth that failing companies can keep their stock price high over the long term with buybacks. The math doesn't pencil out.