Never heard that one before 
We have one âColumbianâ who not only types with one finger, but holds the keyboard firmly to the desk with his other hand, in case it tries to escape while his typing finger is taking aim 
I suppose it depends how many different computer systems (and applications) you have used. Iâve lost count long ago, but probably had to learn a whole new programming language (not just an app!) about once every 18 months on average. After the first 20 or 30, youâve seen it all before and you just get on with it - resistance is futile.
(BTW Iâm no younger than you are - but probably not as stubborn! But I do subscribe strongly to the view that GUIs are for WIMPS - real computer users just ignore them.)
Context menus with submenus solves this brilliantly. And again: once you know the app better, you would want to learn as many key commands as possible.
"The same goes for dragging - how does the app know if by dragging a bar you are wanting to move it, select it, select the items within it, move the items within it, change the spacing or scroll the page? "
Other apps solve that in various ways. Dragging with certain modifiers trigger specific actions, for instance. Or the app looks at exactly where you start to drag/click. Besides, looking at the many places in D. where these solutions arenât implemented - dragging or context menus wouldnât represent a problem/any confusion in most of them.
Itâs obvious that Steinberg/the Dorico team is very serious and ambitious, and I applaud you for that. Really. I donât think there are any other companies or developer teams which are so serious about notation. But I also think that Dorcico sales and popularity may suffer from the program still need a rather high number of hours (much higher than needed with some UI improvements) to be mastered properly, especially for those who donât use it as their to-go program for daily work. But from what I can tell, pro engravers should have every reason to invest the time needed to become fluent in Dorico. Itâs just that (I believe that) âthe rest of usâ is a much larger potential group.
I will say again, Dorico is a very good software. Very fast compared to other notation software.
The ideal software is a software that allow mouse/menu navigation and key commands.
Logic has both
So when you are a pro, writing music 8 hours a day 5 days a week you will be able to use key commands and the other amateurs will use mouse/menu navigation
I am a hobbyist I use many software I can just remember COMMAND C, V and A ; this is all 
A long command in Dorico : 
ALT + COMMAND + NUM + â DĂ©caler ( Left, Amount: A Lot )
another nice one :
ALT + COMMAND + NUM + SHIFT + â Allonger la durĂ©e ( Use Rhythmic Grid true )
This is making me remember the MSDOS and IBM CICS time when I was young
Those commands can be done by just a mouse move !
Welcome back to the sixties
it feels like it, doesnât it?
Actually I bought Sibelius 1.2 (when the first Mac version came out) end of 1998âŠ
I donât mean to disagree with you, but Sibelius 1.2 came out in late June 1999. I remember it well, because it was the first release of Sibelius that I worked on. I remember downloading the installers over the ISDN line to our funny triangular-shaped office above the Co-op Bank on Burleigh Street in Cambridge and staying late into the evening with Ben Finn testing out the builds that Jonathan, Simon, Graham and Yasir were building in the Putney office (which I never visited).
Actually, there were some pretty powerful graphics devices around in the mid 1960s for those who could afford them.
For example the IBM 2250 (launched in 1964) had a resolution of 1024x1024, an early version of a touch screen (called a âlight penâ), and 32 context-sensitive programmable buttons for a user interface as well as a full conventional keyboard.
But in todayâs money, a four-terminal installation cost literally a million dollars!