Valve makes good games. As long as Valves continues to do so, people (like I) will continue to buy Valve's competitively priced games as long as they live up to the quality of the Orange Box and Left 4 Dead, etc.

Think about it, has Valve ever released a game that was sub-par?

People buy six Guitar Hero games a year at $60 a pop, why are people throwing tantrums when a company well-known for quality games releases a sequel to one of their best games ever with so much more content in it?

I'm sure if Valve could release it as an update or an expansion they would, so why all the crying?