Of course they can. What they cannot is force people to sell their shares, but they can buy whatever shares are available in the market. And given enough money, anyone will sell anything.
But people won't sell anything for enough of their own money.
So, look, the value of Apple is A + C, where A is the present value of Apple's business per se (that is, how much you value owning the thing that makes iPhones and sells them), and C is Apple's more-or-less cash stockpile.
Unless you think that A is 0 or negative (which is obviously absurd), Apple can not buy itself. Any money it has just raises the total value of the company. Any money that it returns to investors lowers the value of C, but not A. If 51% of Apple investors want their shares of C, they can literally just choose one of themselves, fire Tim Cook, put that person in charge, and order C returned to investors through dividends -- and they'd still have A.
Given that, why would they accept C money for an asset definitionally worth A + C?
So, look, the value of Apple is A + C, where A is the present value of Apple's business per se (that is, how much you value owning the thing that makes iPhones and sells them), and C is Apple's more-or-less cash stockpile.
Unless you think that A is 0 or negative (which is obviously absurd), Apple can not buy itself. Any money it has just raises the total value of the company. Any money that it returns to investors lowers the value of C, but not A. If 51% of Apple investors want their shares of C, they can literally just choose one of themselves, fire Tim Cook, put that person in charge, and order C returned to investors through dividends -- and they'd still have A.
Given that, why would they accept C money for an asset definitionally worth A + C?