In essence the current refresh rate of consoles doesnt really create the need to really ask for an upgrade every 2 years. Otherwise people would have been asking for it and consoles would have been sharply losing appeal 2 years into their life cycle.
There was no option before, so people couldn't ask for it. People weren't asking for smart phones in 1990 because the opportunity didn't exist, but now they lap them up. Stick an frequently upgraded console out there and for all any of us know it'll outsell the static consoles 5:1.
In addition its only an assumption that games will be well optimized for all versions.
But games aren't 100% optimised for static hardware as it! It doesn't make economical sense. A few 1st party AAA titles squeeze every ounce of the hardware. A few AAA 3rd parties might do the same in a very competitive software marketplace. The rest cross their fingers and hope for the best because it's not economically viable to go down to the metal across three platforms. The vast majority of games sit on middleware. Do you refuse to buy Unreal based games on your PS3 because it's not getting 100% utilisation from the hardware? Are you going to refuse to buy games on your PS4 or XB1 that aren't coded low level enough to get 100% use from the hardware?
Edit: So in an alternate universe we could have gotten a worse version of TLOU on PS3 V.1 and a version of TLOU that is kind of better than on PS3 V.1 that just isnt as good as it should have been on PS3 V.2
In the alternate universe I presented, you got exactly the same game on PS3 which is already over the limits of the machine in terms of what it can achieve at a smooth framerate, and the same game on another machine capable of playing it at a better framerate, giving you the choice depending on how much you want to spend. I was using it to show people would prefer better machines than the ones they currently have.
If PS3 had been 'soft' and the games sat on an API layer, LoU wouldn't have been as good. But as you say, you won't have anything else to compare it to, so a few cut-backs here and there wouldn't be noticed. You'd then see the PS3.5 version which looks even better, and you have the option to upgrade or not. Will you be disappointed that your machine can't play it as well as the new (more expensive) model? Probably. But then people have to live with the constant disappointment of other people having better cars, phones, houses, computers, etc. I don't see why the console space has to provide an egalitarian society where everyone is equal.
If there was a need for an upgradeable console it would have happened already as the market would have been responding accordingly
The technology didn't exist earlier to enable it earlier. It's worth noting that if the market needed an upgradeable computer when every computer architecture was static, they would have, and...oh look, they did. All those static, coded to the metal home computers were replaced with generic PCs. If the market needed an upgradeable mobile technology then...yep, that one happened too. Fixed hardware, discrete products were replaced with versatile ones not coded to the metal. No-one to date has offered an upgradeable console lineage because it wasn't feasible (let of software technology and predictable hardware futures), but where elsewhere across this industry we're talking about consoles being twice as powerful in hardware terms probably not being able to really differentiate to the end users, knocking some percent of peak hardware usage that people probably won't notice to provide full forwards and backwards compatibility, easy development, more consumer choice and greater opportunity for profits from the console companies (can sell higher margins on new hardware while still supporting the entry-level version), it's hard to argue against as both consumers and businesses.