They’re not worried about individuals like ourselves making our own private modifications if we so care to. They know 95%+ of individuals out there aren’t even coders anyways, they just expect the few that do happen to go out of their way to modify their apps don’t distribute their mods without authorization.
The main infrastructure of their license is to make sure the big companies out there can’t legally rip off their code, alter it and sell it under their own branding or such.