Honestly, while the idea of Pac-Man and the ghosts being friends does sound kind of wacky, I don't have a real problem with it. Blinky, Pinky, Inky and Clyde were always popular with fans, and since there's an even greater evil than them on this show, they probably figured Pac-Man needed some allies.
I'm more bugged about 2 other things:
1. The fact that Pac and the ghosts are in high school. The high school setting for cartoons has seriously fallen into redundancy. Do producers really think that the only way to make characters appealing is to make them teens and put them in high school? Maybe it's because I never really dug school as a kid, I never wanted to see a bunch of shows set there.
2. This is minor, but I hope that the ghost Pinky is made a female on this show. On nearly every form of Pac-Man merchandise, Pinky was usually portrayed as a girl, but on the H-B cartoon show, Pinky was a guy (voiced by Chuck McCann) and there was an added token female ghost named Sue (which was Clyde's name in the Ms. Pac-Man arcade game) who was purple. There were never 5 ghosts in the games, nor was there ever a purple ghost. Nitpicky? yes, but that mildly annoyed me as a kid.