Hasbro isn't afraid to take chances with their properties and know that the comics help to keep the brand out there. There haven't been G1 or RAH toys out for years (until recently), but Hasbro kept those brands out there, despite there being no new toys to promote. Mattel, on the other hand, killed EVERYTHING MOTU when the 200X toyline failed, even the cartoon and comic book, which were well received, were stopped. Instead of keeping the MOTU brand out there, alive and prospering in some way, Mattel let it sink to obscurity.
Simon Furman and Larry Hama did great work, but now other creators are writing those books. It is Hasbro that keeps a comic presence with their lines. And now they are starting to do this with video games (if only G.I. Joe can have a good modern game).