Most existing and trained users love it.

I have heard same argument for command line interface in yester years, why switch to Graphical User Interface, when CLI is so much more faster and I love it (and so do my other friends around me).

Attrition (so new employees), interns, fresh campus hires, I guess does not happen in that universe.

No it's not that bad, it has auto-complete, it has search functionalities for both commands and data, and there has been a help button to chat with a bloomberg support person for as long as I have been in this industry.

The Bloomberg terminal does two things which make it much more approachable for beginners than you suggest. Don't know which function you need to do something? Type in what you want (and possibly hit HELP if it doesn't autocomplete for you) and you'll find it 9 times out of 10. The 1 time out of 10 that doesn't work, you start a chat with support and they'll point you in the right direction pretty well immediately.

The one slightly annoying thing is that for a lot of things there are at least 5 different ways to do the same thing/5 different screens with very similar functionality, and everyone seems to use a different one.

But it's also worth saying it's a tool specifically aimed at specialists - it's not going to hold back on giving you a huge number of options over which data you want and how you want it presented, and it's not going to warn you that some data might be incomplete or not the one 'everyone' uses.

Agree with all of this. But the color scheme, screens that distort when resized, US date formats shown to European users, text based graphics, textual commands, etc, would make more than one graphic designer physically sick.