According to the news release “This probably will be the last 5.1 bugfix release, since we’re updating our dependencies and builds after this. Next will be 5.2 with a ton of changes!”
The UI could use some work I agree however there are other parts of software that is being worked on, Krita works enough for me even though I am in no way a professional at all when it comes to drawing software.
ProVersion for ProfessionalUsers in form of AppInPurchase
This would contradict the main point of Krita, to be free and opensourced. If you do have the ability, plugins can be develpoed for Krita to be shared. There are some really good plugins such as Buli Notes and Pigment.O