actually, making those kinds of figs is what keeps the toy line alive. If they just made turtles that looked like the first wave, they wouldnt sell. Occasionally they can get away with new features (like the mutations and ninja action re-paints from the 90's), but kids buy toys and kids want stupid costumes and weapons that dont make sence.
The turtles line has also been pretty good about making figures that appear in the show aswell as kid-targeted figures.
I think if GB comic figs were made, they would prolly be one shot deals, the four GB's in comic likeness and thats it. I wouldnt expect a long line of toys that would produce flying ninja action ghostbusters.