MuseScore - what is it missing?

Hi all.

Just wanted to ask a general question about scoring software.

I've been using MuseScore for a couple of years now, but have been told it's not capable of producing an engraving to professional standards.

Just wondered what features it's missing that would be essential to professional quality work?

I'm curious to know who made that comment.  I can't really think of anything that you can't do these days, at least through manual adjustment.  Maybe if you are doing really funky contemporary scores that deviate from standard sheet music styles, but that's not going to be a problem for most people.  Then again, I'm not a publisher or a professor, and they are allowed to have a standard program that they prefer to receive files in to make their lives easier for marking up scores, editing, etc.  Sometimes something is the standard just because at some point it was the most commonly used, and it's annoying to switch between different programs all the time which aren't compatible with each other, not because one is actually better.  

That said, I'm annoyed at Musescore every time they come out with an update and they move all the features around so I have to relearn where to find things.