Prolly cuz Scamco-Canlie are awful at milking their brands.
Actually they seemed to do a decent job at pimping Pac-Man. Short of doing new updated to its age open world collect-a-thon AAA games, they pretty much kept the ectasy swallower relevant. Meanwhile Konami has forgotten Bomberman in whatever cellar they locked him in. :'(
Pac-Man 256 is pretty great, the Pac-Man Championship Edition shows just how solid the core gameplay is. It is an amazing core mechanic.
I helped make Pac-Man World 3D for PS1, and a little of Ms. Pac-Man Maze Madness, and it was frustrating how the local western management didn't understand what they were dealing with. We also tried updating the character, actually it was similar to how Mickey has been changed for the most recent range of digital shorts and games -- but local management forbade us from presenting it to NCL (Japan).