There was a reason, once upon a time, but then no other preference manager involved ever surfaced. There was a bit of protest when I started deviating from Support_Updater when working on v4.0, and the next update is integrating Support_Preferences a lot more seamlessly. The add-ons are even packaged together, the only difference is namespace.
It's incredibly frustrating to work with and it really just seems to confuse everybody.