The same is true of most companies - there's exceptions to every rule and most of the time you have to jump through a thousand hoops first and it often depends on the person who's serving you.
The thing that always amuses me is that when Valve says no to 99% of people that contact them it's a non-issue. Someone like (off the top of my head) EA will say no and it becomes front-page gaming news and an injustice against humanity.