Well if some people would read the review and my comment fully . . .
The market for third-party CPU coolers has flourished in recent years while the market for third-party GPU coolers has stayed remarkably niche. Many reasons explain this trend but primarily it is due to the effectiveness of cooling solutions that ship with retail graphics cards and, to some extent, the technical complexity of fitting a third-party GPU cooler that acts as a deterrent.
I think you've missed a couple of points about the lack of market for third-party GPU coolers.
To start with not just the technical complexity but also the legal/warranty issues involved with replacing the cooler.
@Ryan Martin, I still say my points stand, when you buy a cpu, you get a stock cooler with it, sometimes you can get hold of OEM cpu's without coolers but it's far more rare and I don't know of any one/place who sells cpu's with aftermarket coolers.
Yes, when a new model of card comes out stock card and cooler is probably your only option, but within a month and cards with aftermarket coolers appear and can often be around the same price as the stock cards.
You've actually summed up the big hassle with warranties
no warranty stickers have been damaged.
common practise is to stick said sticker over one of the screws that hold the cooler on, so you cannot change it without voiding the warranty.
Also the only company that openly allows you to replace the cooler without voiding the warranty is EVGA (allowing that the card still has issues with the original cooler reattached and no physical damage is done to the card)
Other companies might turn a blind eye as long as there's no physical damage and you don't admit to removing the stock cooler, which is not the same thing.
Overall the review was excellent :) I just think that the availability of non-stock cards are bigger factors in graphics card coolers being a more niche market than the complexity of fitting them or the effectiveness of the stock reference coolers.
The next big issue is the Total Hassle involved, not just fitting it, but the added cost of the cooler, making sure it will fit (ok not a big factor, but a factor of the total) the added worry that you'll do it wrong and then have trouble with your warranty and the fact you can buy non-reference cards for near enough the same price.
One of the things you can do is to look at the cooler market, there's very few lower cost options, just the high end coolers, I think the main reason for this is that the manufactures are already using the coolers which would of been the mid range option which has turned aftermarket coolers into a niche market.