Yeah the whole 8 belts in 8 weight classes is bullshit. You win titles at the weight limit..hence "welterweight title" or "Light middleweight title" - not by making a light middle fight where your opponent (punching bag) can only come in at 150.

You fight for belts at the weight - If you want a catch weight, no title should be on the line. Greedy alphabet organisations are just as much to blame.