We really only have Nintendo and Sony to base that assumption off of, and no more/less.
Sega didn't do good with the SMS, did great with Genesis, then did very bad with Saturn and DC. Nintendo did great with NES, SNES and somewhat good with N64. We still have yet to see how badly PS3 sales will drop off compared to PS2, ect.
However, I would agree that it seems the virus of failure is that these companies try to cater to one gaming theory (not actually market), and stick with it. I guess the reason is that they have found succuess with one method, and feel that the one method will work, when gaming trends change. In the NES days, games were a kiddie machine. Earlier still, they were a teenager machine. Now they are an everyone machine, and only the PS1/2 really was able to capture all audiences.
Atari failed at the 5200 and Jaguar. Nintendo failed at Virtual Boy. Sega failed at Saturn. Microsoft has yet to fail. Sony has yet to fail, but seems very likely this generation.
Back from the dead, I'm afraid.
