The difference between Console and PC games is being able to sell your games. With the invention of CD keys, they may as well be digital. People choose console for a number of reasons. some of them for the lower price point, and some of them because they can pawn off their games every six months to a year (sometimes less). Especially sports gamers.
Steam is still alive for two reasons. One, like I said before, you can't sell PC games anyway after the CD key has been redeemed. But the other is the main reason. Steam knows the draw of value. Steam has sales every. single. day. Borderland is on sale every other month. Valve games are on sale all the time too. Quality games for awesome prices. I gotta be honest, sometimes I feel like I'm stealing when I buy a game for 10% of it's original price. Steam has that shit down.
I have to say though, I don't see Sony, Microsoft or Nintendo mimicking Steam's insane deals. I, however, would love to be proven wrong. If MS can match value games with Digital prices along with some killer deals at least once a week (not this shitty XBL sales crap they're doing now), they may be able to make a profitable system. Even a gradual price drop on all titles would be awesome. They need to understand that just because they are the only game in town, doesn't mean guaranteed sales.
Before Steam, you could just resell your old PC games too. In fact, Steam basically killed any used market that existed for PCs. But people love the damn thing since the sales are great and the service itself is awesome.
Also, nowadays, games are becoming and less and less resellable nowadays. Online passes, undeletable saves, all this stuff is making a used game a lot more undesirable than a new one. Difference is that people complain so much over an online pass but won't think twice about having an entire game unplayable unless you enter a code. The reason for this, as I mentioned, is that the prices are so good. Why worry about the resale price of Mass Effect when I got it for $5?
There's just a lot of double standards when it comes to console gamers and PC gamers. For PC games nowadays, it's almost standard to come included with some sort of redemption code or method for Steam, GFWL (hold your laughter, please), Origin, whatever. Without this code or method, the game is a coaster. If any console game did this, there'd be an uproar. And yes, piracy is a factor since it's pretty much always easy on the PC, requires no modifications to the system itself, and you can't suffer dire consequences for it (in terms of being banned from online services).
I think eventually gaming will turn entirely digital. There's some small strides being taken towards becoming a Steam-level of sales. Look at the Vita. Digital games are cheaper than retail. While it's not the $10 difference that often comes to PC copies, it's a step forward.
I think the issue is how the companies view digital distribution currently. Valve sees it as "We're not giving them any physical ownership over the product so we'll discount them for it or provide whatever benefits we can". Microsoft at least sees it as "We're giving them the game almost instantly instead of waiting for delivery or having to go pick it up so it's a benefit to them". I think over time people will turn to a Valve way of thinking. They've made constant strides to go from a rather small time developer to colonizing PC gaming as it is. This didn't come from overcharging for their products, it came from smart business. Turning games past their profitability into free to play or by selling them for pocket change. Providing constant discounts that retail can't. Giving them easy access to tools to modify their games and let them turn into virtual Model Magic.
For the record, no matter how badly I presented it, I totally agree with you.