While yes the company can certainly do what they want - that isn't to say that everything they want to do is correct.

In an isolated bubble their decision looks... fine.. ish. The reasons they provide are mostly excuses- but for arguments sake let's say it is actually making a meaningful difference. (It isn't and won't: TPM is flawed and has already seen demonstrations of exploits.) So we now have a platform that has locked out users based on OS version, hardware support (TPM), in addition to os. They are actively culling users that otherwise were viable customers. Smart.

Let's expand on this outside the bubble: what os is growing rapidly in usage with gaming? Linux. Riot is actively making a shortsighted decision (historically this tracks) which will cause them grief in the long run. Remember: their games worked on these platforms prior to this decision. The support was all free labor done by the community. Let's say they want to release a game that takes advantage of the handheld platforms that are rising in popularity- they now need two separate anti cheat systems. Oops. They now need to try to claw back the early adopters and free community support they burned. Good luck.. Factoring in the cost of limiting future flexibility and growth... I can only imagine the game experience must have improved 2-3x by the addition of this anti cheat ... except it hasn't. By their own admission: cheat developers move faster. Objectively? It was a terrible decision.