Depends on the game.

Isn’t Sailfish OS already pretty much “a Linux phone that works”?

Familiarity.

If an alternative isn’t 100% identical to a tool one is used to, one automatically has reservations, and the slightest inconvenience immediately turns into a blocking issue. On the other hand, one is typically inclined to ignore problems with tools one is used to.

There isn’t much one can do about this, other than trying to keep an open mind, and being aware of that bias.