Your belief that 60 FPS (or anything above 30, really) will somehow lead to "not playing anything new until 2030" is, to me, nonsensical. If you want to elaborate on why you think that way (possibly providing examples to back it up), I'd appreciate it.
Given that consoles will guarantee native 4K, that graphics can't be worse than now (otherwise mass market won't see them as an improvement, fairly I might add) and that they can't cost more than 500$ (400 is not enough to have improvements compared to xbox1x), you need to squeeze all the resources in those dollars. If you aim for both 4K and 60 fps you won't have much left to improve anything else. If you accept 30 fps (as it's been for the last 10+ years, given that the vast majority of console players doesn't give a fuck of 60 fps except for frenetic games), then you can use the remaining resources to improve other aspects of gameplay.
I like the sponge metaphore though, it's actually the best thing of consoles: optimization. Having a fixed hardware, during consoles' lifetime you observe a drastic improvment in games thanks to software houses learning how to use consoles at their best. Look at how games looked like in 2013-4 on ps4 and compare them with RDR2, or uncharted 1 vs uncharted 3 on ps3. If consoles had a shorter lifetime (3 years? less?) this wouldn't be possible, they'd just say "you want better graphics? buy the new console", and we also need to keep in mind that most AAA games now have longer development times than 3 years. Plus, mass market refuses to spend 500$ every 3 years for a console.
it's the nature of consoles that prevent progress from happening.
this is the typical argument that to me makes no sense market-wise. It would be true if every PC gamer played on high-end PCs (and we all know it's absolutely false, check steam statistics) and if consoles were only a small part of the market. The reality is that developing a game has become much more expensive than 20 years ago, if we don't want to pay 100/150$ for a game like in the '90s (considering inflaction that was the price for ps1 games in my country) we need a lot of people to buy games (kingdom of amalur failed because it sold "ONLY" 2 millions copies). Now, no need to explain why mass market is not willing to buy high-end PCs only to play videogames, just imagine how many people would buy videogames if they needed to spend 1000+$ every 3 years because, hey, technology runs, we need to keep up or progress stops. How many of those 90 millions people who have a ps4, 60(?) millions of xbox 1 would have spent all those money to play videogames? Don't tell me all of them, it wouldn't be true. And what about people playing on low/mid-end PCs? I don't even think it's realistic to expect less than half of those people to spend all those money for gaming. But let's pretend that half would do that. Videogames' development would have the same cost, of course. How many copies they'll need to sell? Same number but with half of the gamers? Not realistic. "Only REAL mater race gamers would stay, buying all games?" Again, not realistic and we need market to expand, not to stay still otherwise companies wouldn't invest at all, basic economics. 3 options then:
1) higher prices (PC gamers would love it, like no one buys russian keys);
2) lower costs (=lower quality);
3) f2p games with microtransactions (already demonstrated it works = mobile games and fortnite).
And all of this just to make few technology enthusiast happy? No, thanks, I don't think it would be progress, but a regression in quality. Why do you think every company is bringing their games on consoles? Why do you think consoles costed only 400$ in 2013? Because SH and hardware companies want as many people as possible to play, gaming only for rich people (and willing to spend/waste their time in building PCs) wouldn't be susteinable by the market.
Games are developed for the highest number of gamers (consoles+low/mid-end PC), if you have a better PC you can push the game to better graphics, fps, whatever you fancy. A good compromise not to see the industry reduced to shitty mobile f2p games.