Earlier quoted context omitted.
But they are not selling the game for Linux. Only for Windows. It's another story that it works because of Proton but technically they don't support the platform at all. https://store.steampowered.com/app/304390/FOR_HONOR/ https://www.ubisoft.com/en-us/help/for-honor/article/system-...
So they should have to return the money you paid, to account for their mistake in selling you the game.
i hate ubisoft as much as the next person, but if they listed the game as only supporting windows when it launched, and someone bought it for linux despite it not being supported, ubisoft did not make a "mistake" in selling the game to them. the buyer made a decision to purchase the game for an unsupported system.
(the rule i follow, which hasn't gone wrong yet, is to avoid all ubisoft games like the plague)
edit: am i missing something here? those disagreeing, please let me know why you believe you deserve a refund in this situation, knowing that ubisoft only advertised support for windows.