A “good” idea would be to have Jolla allow for chum to be activated through the setting in the phone (Untrusted Software) and NOT allow for a gui so that you somehow know what you should do with the command line in order to install stuff.
But i doubt this would be popular with Jolla.
Fragmentation is a problem and the main cause of it is that Jolla hasn’t found a way to work with the community on the OS. Hence multiple “stores”, multiple solutions to functionality and other issues. And the result of that is an OS that is inferior to what it could have been.