... for modest values of "fine". Compatibility, stability and performance have improved immensely the last couple of years, for a large part thanks to Valve!
Yeah, WINE may have been around forever but its development was massively accelerated by Valve dumping truckloads of money on CodeWeavers to have them work on fixing games full-time. Plus neither of the two most popular anti-cheat solutions worked in WINE at all until Valve lobbied them to support it.