Two reasons come to mind, whether they are “good” is for you to decide:
1.) If you rename from “specific” to “generic” you lose information. My folder is presently called PT8 and that is telling me that it was initially created (most likely) with Paratext8 and that I might find some specific stuff inside that originated from Paratext8 and might no longer apply to Paratext9. You can also tell that I do not like long paths at the root of complex projects.
The new PT concept seems to be that you start with Paratextn and can update for one or more generations on the same data. So for technicians and support staff it might be helpful to know the depth of the local “history” at a glance.
2.) Second reason: Every change has got inherent dangers, that are typically not obvious before or even right after the change is made.
A few days ago, we discussed PT icons here and my personal conclusion was that icons should be removed altogether because people agree that they do not communicate and need to be “learnt”. So they just take precious screen space. It is clear to me that such a deep change like removing all icons sounds great but will most likely cause some unexpected trouble down the road. Not worth it at the moment; I did not persue the subject.
Ask yourself or other users what actual benefits you would gain from the renaming of the PT projects folder, rather than “why not?”. There is wisdom in the saying “never touch a system”. (Oh bother, I sound old now.)(If there ever is a new radical generation of PT with all those amazing new ideas included, like no icons, keyboard-friendly-ergonomics, then I hope it falls into a phase, when I can make some time to help with testing.)