And even less understandable is the limit of 10 Group Quick Keys for those 20 groups. You can have 20 groups, but only 10 of them can have their own Group Quick Key.
I don't want to play down your complaint, but at least be fair and ask why 20 groups per system.
Max groups per system = 20 * Max systems = 500 for a total of 10,000 groups. (Systems can be duplicated placing PD in one system, FD in another system, utilities in a third system, and so forth...)