Why? it's overpriced by $100. Has about same performance as GTX 570 which you can get right now for $250 or $110 less.
I'd pay $50- extra for better noise levels, OCing ability and power consumption so that still puts it $60 too high.
-On the contrary, many of the vendor cards are have a decent 10% OC on them, which actually has the 7870 trading blows with the GTX580 and even the 7950 in many scenarios (see the recent Anand review of the PCS+ and Saphire variants). Its more or less a $350 GTX580, and an absurdly good deal for anyone looking for that kind of performance.
I agree that everything would be much more wonderful if we could pay less for it, but for someone looking for that kind of performance its a steal.
I on the other hand, will continue to wait for double my GTX460's performance at the $200 price point.