Perhaps you have a point about the Gamecube and gb still being sold, but to my knowledge both don't have tons of games coming out in the near future or is there still any publicity about it. Can't remember seeing any gameboy advance commercial lately, but the PS2 is still actively being advertised.
Any product that is actively sold and promoted is a part of the market and should get credit for that. If the PS2 had a X year head start is irrelevant, at least that's what I keep hearing if I mention the 360 had a year head start over the PS3 and Wii.
Both the DS and PSP were released before the next gen, as you refer it too. Their sales should be hidden too, according to your logic.
PSN name: Gazz1979 (feel free to add me, but please put your Vgchartz name in the message!)
Battlefield 2: Gazz1979
