This is only partly true. For example, my PC is probably more capable than an XB1 or PS4 as it stands right now.
Likewise, in another 12-24 months, PC's will have moved forwards and consoles will not, so even though they are technically similar to PC's we will once again see the hardware limitations of consoles holding back the true potential of PC games. Software developers will not have the time or inclination to make PC specific versions of titles for a 'minority' of gamers. It would not be good business acumen. It is a sad but true fact that the proliferation of consoles whilst bringing gaming to a wider audience has also lowered overall standards in the games that are made today because of hardware limitations.
I believe that there is something different this time that needs to be considered. The fact that the
architecture is much closer to PC's this time is very important.
What do we mean when we say "held back"?
In my view a few things:
1) Detail of textures and their need for enough graphics memory
2) the need for a solid multi-core CPU
3) their need for RAM
4) possibly physics processing
Now, undoubtedly, we can say that the specifications are already behind top flight PC's but the architecture is so similar now that the difference between current consoles and PC's is more akin to the difference in what a standard PC game must cope with with regard to lower specced PC vs high end.
the only important thing that concerns me, that cannot be sorted with higher specs, is how much effort they put into textures..these will only be made for the consoles in the main and PC users will need to wait for extra, higher quality, texture packs if they ever come.
other things such as number of objects on screen, quality of shadows, reflections, AA, because modern consoles have these, can all be switched off and on at the leisure of the developer and I the case of PC's the developer must simply put an additional few graphics options onto the options menu.
edit: there is one other key arena, of course: Direct X - games pushing the latest greatest version of this tech will be more scarce as they truly are features that take a lot of time for PC specific development. most games will be stuck with Direct X 11x for a long while.