It's an OK thing as long as Valve maintains its current corporate climate. Eventually they won't, due to the old guard retiring and new people with different agendas taking over.

I don't think Steam being spun off into its own company is the answer, because their current setup will only remain benign as long as the current Valve corporate climate remains in charge.

Personally I try to buy directly from the developers whenever possible, which usually only applies to indies.