I hated it that they blew up the Enterprise. One of my beefs with all the movies is that the Enterprise was never really grand it always ended up getting pumeled or destroyed.
Uh...it got destroyed for a very good reason in Trek III though -- because Kirk was trying to save his f'n life. One of my favorite scenes of all Trek when the Klingons walk on to the bridge and find the computer counting down to 0. And Kirk is obviously upset at having to have destroyed it. Very dramatic.
And it was better than having the old girl scrapped, which was what Morrow wanted to do to her.
I remember there being talk going about back at the time (early 80s) that got picked up on by some novel writers and the writers for DC comics that the Federation and Starfleet were undergoing a severe internal crisis, centered around it's becoming less and less of a "frontier" organization and starting the process of becoming a "mature" one.
Advances in communications meant that the local Captain on the scene had no excuse NOT to radio back to Headquarters for instructions on a regular basis, even duing crisis situations. "Cowboy diplomacy" (as Picard would later referr to it while speaking to Spock) was on it's way out the door. In essence, we were witnessing the beginning of the death of the TOS Federation and the birth of the TNG Federation.
In that contex, Kirk and his crew were seen as something in the nature of throwbacks to a way of doing things that was no longer in vogue
with the Federation Powers that Be. Prior to the Genesis Incident, their record of success sheilded them from too much criticism.
Kirk comes out of the Genesis Incident looking weak and vulnerable, so the elements that were working towards his ouster seized the moment. That was why Kirk couldn't get an answer to the question of getting another ship. That's why Mr Adventure referred to Uhura's carrer as "winding down".
Kirk and company were to be basically swept under the rug and KEPT there. Only the "Whalesong Incident" saved their collective bacon.