Who designed these bloody jockey wheels to collect so much gunk!

Now, my bad x2 – first being that I used Muc off wet lube and continued using it as I didn't want to waste it, and it's the worst chain lube ever made. Second being not cleaning the drivetrain as often or as deeply as I should have. But good lord!! Why are the wheels designed like this, with little cubes to hold all the dirt?!