I reckon that the Powerspot being discontinued is probably because (in my opinion) it isn't as Iconic as the Scooped bats were. And many of us have very bad memories of Powerspots with very small middles that it was hard to hit the ball off the square with.
Add to that that it is a traditionally shaped bat (and we know how successful the GM 1885 was) and I think it didn't ring the nostalgia bell as well as it might have. Certainly not in the same way as the Scoop and the Dynadrive.