Price.

This is all that matters.

Those things are going to be a hilarious flop.

it wont happen, because low end steam boxes still cost a lot and are just glorified streamboxes that need existing high end pcs, and high end steam boxes cost a pound of flesh.

wont impact the console space at all.

What's the point if you can plug your pc on your tv? (Honest question here)
The customisation is cool for some people but might lose a wider audience : some are already lost between PS4, XOne and Wii U, I can't imagine with tens of Steam machines. Simplicity is a key to success IMO.

cool story bro

Valve was kind enough to give PS4, Xbone, WiiU a head start. Nothing to do but embrace obliteration now.

I think that Valve has chosen the same business model than the 3DO and that didn't worked well. They also managed to do some more abysmal errors:
- 2 year advantage to PS4/X1, with 20M+ advantage for PS4. The consoles now have a library and maybe will even get a price cut this year.
- SteamOS. A selling point would be the amount of games, but they managed to remove this. WTF. PS4 and X1 actually have MORE games than SteamOS. They will launch the machine this year without COD, Fifa, Assassin's Creed, Need for Speed, etc. Summer Sales aren't useful if all you can buy are some indies and 10 AAA games. That's simply beyond dumb. People buy consoles to play games. SM are one of the most expensive ways to have no games.

I simply can't see where this fits. The current Steam diehard already has a rig. It's cheaper than the SM and more compatible with games. I also doubt that PC gamers want a more console-like experience. If they did, they would already have consoles (something that a lot of them may have). In the other side, I don't see why console gamers will jump to a machine that's more expensive and won't run almost any game.

The manufacturers you talked about are another problem. IBuyPower, Cyber, etc. Do you really think that the average consumer will trust an unknown name instead of something like Sony, MS or Nintendo? Again, 3DO approach with predictable results.

Valve's approach was as lazy as possible. It simply looks like a desperate attempt to get away of Windows because MS now have an app store on it and Valve surely fears that MS will lock them out with a more Apple-like approach or that they will start selling games on the system with a pre-installed app (basically, how they screwed Netscape. Even if you sue them, you end up bankrupted before the result).

Just to finish, this is the 3DO approach's problems that I'm talking about:
- There were several manufacturers. They were all part of the 3DO company and the royalties were split equally. So each manufacturer had to sell the 3DO with a decent profit margin, so it was more expensive.
- It was Panasonic, Sanyo and Goldstar behind the console. But they branded themselves as the unknown 3DO company to fight household names like Sega and Nintendo.
- Expensive console with few games.
- Arrived mid-gen.

Valves just checked all these disasters. So my prediction is a shameful flop.

Nope they dont need to. Steam machines have no exclusives, are overpriced and dont support offline gaming or physical media.
PC fans wont buy them either as steamOS lacks a huge part of the steam library, why should some one game on SteamOS and lose 70% of the library?

They cost too much, plus the fact that there is too much choice, only specific people will buy it.
There is a lack of local multiplayer, and it will not have a marketing as strong as a console.
It will probably not change the console market in any way.

the Steam Machines will fail and that is a fact