you have a point, but throwing money (problem or not) seems to be our way, no? (><)
Oh definitely and that's what some people do. Watch Dogs was prompting folks to question if a 6gb 780 or Titian or swapping to AMD and a 290x would ease the stuttering issue despite owners of those cards also reporting exactly the same issue when they're weren't even close to running out of resources. Then there's the new found zeal of the nothing less than 60fps crowd who won't compromise some graphical features for their beloved update. A time comes when you have a trade off when you can't have your cake and eat it. The Witcher III is odds on to be in this camp where I'm going to go out on a limb and say that at release no combination of GPUs is going to max that game out at 1920x1080 unless you're willing to reign in some settings.
One of my favourite parts of getting a new GPU is letting it loose on older games and see what you can really push out of them (hence my crazy Dead Space series, DMC 4 and RE5 experiments some threads ago). Even more so to hook up my 120hz monitor and experience a fast update with no visual compromise.
But hey each to their own. I spend my money on some crazy things so I shouldn't chastise others if that's what they want to do.
Getting the 970 was Jase's suggestion based on US economics. It absolutely doesn't make sense with euro economics and my idea was always getting a second 780 next year sometime. Not because I need it but because I like spending money on stuff, and overkill is always nice for the lazy among us.
Oh for sure I know what you mean and with Dynamic Super Resolution, which is driver based downsampling, you won't really be wasting any performance at all as there's always higher and higher rendering resolutions to go before no aliasing is present. But then for me the frequency of updating and a yearly, 18 month cycle is nuts as you could get buyers remorse when the 1070 comes out a year after, then when the 1170 pops up 2 or more years later it's all over again and rice and repeat.
Even going with US prices it still doesn't make the upgrade one of substance on what you gain for what you could by waiting it out a year or two. As you said Metro 2033 is the only title you personally need a bit more performance so how much is that worth? Though I think we can all agree some (maybe most of us in here) like new toys to play with so the temptation is easy to see its just how rational a decision it is for each any every one of us. For me it's an irrational decision but if someone gains happiness from doing so then that's none of my business.