Perhaps editing existing drawings and messing around trying to gather information about the rules is just too much of a hassle for most people given that they may only go through the process once only, but as with many of these types of things, the initial consumers would probably be professionals looking to speed up their workflows by using boilerplate materials that
I did notice the restrictive default contract terms for an architect we used so would not be giving away anything I did not create myself or own the rights to. Funnily enough, the contract was almost certainly a copy of somebody elses contract...
From an outsiders point of view, it sounds like the people on this forum who know the industry are quite happy with the situation where small building changes seem to sit in an odd area where homeowners must try and build with good design, but have relatively small budgets which means that architects can only spend a trivial amount of time on most small builds... and then the designs which have little reuse value are protected with the most stringent of copyright clauses. From a homeowner’s point of view this system seems poorly thought out.
Alternatively, the designs do have good reuse value and should be protected since they are a valuable asset. If this is the case then sharing designs when you can would make sense for homeowners in general... do retiring independent architects just take all their designs to the grave then?