Steam and their various games

Steam is a fabulous service, the market leader.

But the products are really iffy. I have a number of games that simply do not play on my PC.

Max Payne 1
Max Payne 2
Serious Sam 1 HD

Others are wonky in one way or another, like they sort of work, but have some serious problems and halt for some reason.

Alice 2 (I reach a point where I have to use a custom item, and it simply doesn't do anything)
Batman Arkham City required a mouse that has a different kind of "middle button" than mine.
Supreme Commander 2 has some problem (I forget what was wrong here, but it wouldn't do something).

Do they not do any kind of testing? Or have some minimum testing requirement to impose on game creators to make an attempt at compatibility?

Some work just fabulous

Skyrim
HL 2
Torchlight 1/2

Given the qty of either total or partial failures I've encountered, I only buy games there when they are low-priced, under $20.

And why do so many games insist on installing yet another version of Visual C++ Runtime? or some variant of DirectX? I'm always a little nervous about this.

Wish there was a way to get the broken ones fixed. Or send them an email saying "BROKEN!"