I would have to agree with the OP.
I do mistakes and non-standard RT all the time (I think we all do), but if there's one thing I try to do is to keep it short and without ambiguity, reading back the necessities only.
The other day it was mad busy on the LARS frequencies, and I was appalled at how many pilots goes on for hours after the initial "pass your message". It's inconsiderate - that time could be spent handing out collision avoidances and much needed traffic information instead.
Personally I have a tendency to not use my callsign at the end of direct established communications. I should become better at this, but I don't feel it's a huge safety issue:
Lydd: G-ZZZZ, report passing Tenterden.
Me: Reporting Tenterden.
It's wrong of course, but there's no ambiguity and not much risk for a misunderstanding as he's addressing me specifically.