The only thing verboten is the pairing of the frequency with the channel designator in the clear. Often times the frequency or designator is given over the air in the clear, just not together per the rules. Can you monitor often and put 2+2 together? Sure. It's not a 'secret' but it is technically classified as FOUO, which stands for "For Official Use only" and is only classified when the frequency and designator are used together.
I wouldn't go as far as to call someone 'full of themselves' just because they were given orders not to divulge said information. Following the rules is hardly reason for a verbal evisceration.
Careful listening will likely net you a few freq/designator combos. Does our 'enemy' have this already? Likely, but I am not a foreign spy so I cannot confirm. Why make the job easier for them? Collect your 'intel' and share it with your friends, but respect the wishes of your military and do not divulge this on an open forum. Post your freqs, but leave some of the fun to the other listeners, and let them decide if your published frequency is Army, Navy/MC, or Air Force MARS, and certainly do not post the designators.
--Former USAR MARS