Even if it’s maybe not the most morally right thing to use pirated software, and yeah, it’s good to support game developers — you’re not forced to buy the game. Unless you’re planning to host a server for it or something.
That said, it’s pretty obvious no one’s making you buy a legit license. There are well-known ways to play this and other games without paying for a license.
But also, it should be clear that if you go that route, you’re not getting any support here.
Personally, I think it’s just more convenient to have games on Steam, even if some — like parts of the Call of Duty series — can’t be played because of stuff like RCE exploits.
