Yeah, not all games work on Linux in all situations though. It depends for example on

• which distro you have,
• whether you have an Nvidia or AMD GPU (for example, SWTOR evidently runs fine through Lutris, but didn't last time I tried with an Nvidia GPU, so that might better with AMD—same thing happened with Dragon Age: Origins)
• what driver for either you have installed (Nvidia is getting better, but good gods the flickering could be better with some of their driver versions—games may play without being playable, after all),
• whether your computer's firmware is even Linux-compatible, let alone Linux-friendly (I know Lenovo laptops used to suck in this regard—they might still, though I don't).

So, no, although it's gotten a LOT better in the last 5 years, the notion that it "just works" is only situationally correct, and is by no means correct to the extent that justifies ridiculing those who say that it is not so plug-and-play as what is claimed.

Furthermore, doing so only sets up new Linux users without the optimal hardware or firmware for disappointment due to unrealistic expectations.