Actually the tech in Xbox 360 surpased PC for the first 6 months of its life.
There was also a time when consoles couldn't come close in graphics to arcade machines too.
In the past yes but we aren't in that kind of situation anymore, back then we could get something very powerful and the hardware makers would eat the extra cost up front. Now we are in a totally different situation, there is no way we can get the most powerful GPU's in consoles even if MS and Sony were willing to lose hundreds (a top end GPU on it's own costs a lot more than a One X) up front because the heating and power consumption issues would make it impossible for something like that to fit in a console. We can still get powerful machines but nothing that's going to compete with what the highest end PC's are capable of on paper let alone going well beyond which is what native 4K AND 240fps would be doing.
I say on paper because games are still going to look really good they just aren't going to be native 4K and 240fps. I doubt we'll even see 60fps targeted a lot, they'll likely use the extra CPU to help push physics or alpha effects etc more.