greenmedic88 on 23 August 2008
Because EA did the port, not Valve. Any updates/patches would have to be at the behest of Valve, essentially saying for EA to use their resources to improve a game with now flat sales for a zero return on investment.
That's the inherent problem with handing off your IP for an outsourced publisher to work on. Once you do that, it's essentially up to them to address any fixes and improvements.
Valve keeps the updates coming because IPs like TF2 are their properties and they want to provide the best experience to its players. That approach has worked pretty well for Valve so far.
