If you bought a 5870 without reading any reviews or benchmarks for $400 a year ago
and buy a 6870 for $230 now without reading any reviews or benchmarks what so ever expecting a huge increase in performance
Then you are only yourself to blame, and where i come from stupidity is not rewarded.
AMD has explained it over and over how and why it was done, and it makes perfect sense with the 5770 already being down to $140 while having 4870 performance ( which still kicks butt ) to be rebranded cause there simply was no room to remake the series or to sell it as a 6670.
It takes 60 seconds to google a review, check the benchmarks, check the conclusion.
If you spend $400 and now $230 that easely without even knowing what you bought you are yourself to blame. And if you really think AMD did this to screw people over ..... then go buy nvidia, but that isnt an option now is it