From what I've seen, the two main reasons are as follows: 1. Bungie is worried about cheaters and hackers Cheaters and hackers primarily use Windows for their cheats, since thats the most popular OS right now and thats what most everything is written to be compatible with. Deciding to try and cheat on linux is just an extra headache of trying to get the cheats to work through the compatibility layer. Additionally, BattlEye has official linux support, which is just one email away. There are also multiple games which use BattlEye that run just fine through proton. Same with Easy Anti-Cheat. 2. Bungie is worried about time, effort, and resources Im fairly certain that more effort has been spent on preventing linux users from playing than would be spent on supporting linux. Given that multiple people in the past have gotten Destiny 2 to run just fine (albeit before getting banned) on linux without any support from Bungie, the effort required to support linux would be little more than removing the intentional checks to prevent the game from launching. Steam is already doing the heavy lifting, and if theres any issues then affected users can report it to the Proton developers as with any other game. Both of these reasons are, in my opinion, terrible excuses. If anything, linux support would be a boon to the game because of the linux community's tendency to provide extra details in bug reports, as well as a small boost to the games playercount and purchases. Ive put over 1.5k hours into Destiny 2 on Windows. I wish I could play more on linux. You're only harming yourself, Bungie.

I finally switched to Linux months ago and the only game that doesn't work is "Destiny 2". I had only recently purchased some expansions. It's a shame, but that's just the way it is. So the game died for me for now. There are plenty of other good games to play.