If your water solution gives you lower temps at lower noise with a higher perf/price than Air Cooling, then you are addressing the problem.
The big concern some people have, myself included, is the idea that this "solution" is now increasing the footprint of the GPU in the system, now expanding beyond the idea of a double- or even triple-slot cooler in the expansion slot area, and going for space elsewhere in the system. Some will be happy with this, but you cannot tell me you don't understand why some will not be happy.
This isn't the same as moving from simply heatsinks to heat pipes to duct-forced external exhaust to more extravagant heatsink/fan coolers. This is now going beyond that, moving from direct-mounted cooler assemblies, to placing the brunt of the cooling effort somewhere else entirely in the system, requiring tubing to that place and taking up fan slots. In many cases, to maintain proper airflow, this may often require a user to already subscribe to the idea of closed-loop cooling, because some cases won't fit the radiator/fan combo when the user is using a large CPU heatsink.
I myself an limited in what I can do, and for these card+AIO packages, I can't fit them, at all. I find the idea that I have to change my CPU cooler to now accommodate a GPU cooler a little absurd.
I am looking at getting AIO for my top (crossfire) airflow-starved 290X Lightning, which to minimize cost and have something fit, that would have to be an H100. That allows me to keep my NH-D14, and that would fit above it in my case. I can't fit one of the thicker rads, and I certainly can't use a rad like the one in the 295X2 on the rear panel, not enough space at all with the CPU cooler.
My next build, which I might make with Skylake (which might be a fitting time to move from Sandy Bridge), I may transition that H100 to the CPU and a) have a motherboard with more slots between the primary GPU x16 slots, and b) have a case that offers more room from the start. Though the Corsair Carbide 400R is not tiny by any means, I rather like the size.