Has there ever been a decent explanation, both in terms of show production as well as in-universe why the Star Trek universe is flooded with Miranda-class starships in the time of TNG/DS9/Voy but seldom (if ever) populated with Constitution-refit-class ships? In-universe, the impression I am under is that most Con-refits were indeed just that, refits of existing Constitution (original)-class ships that had already been in service 30-40 years prior to the refits, then served another two or three decades post-refit (there was interesting conversation vis-a-vis the Enterprise-A of ST5 being a newbuild versus a refit of an existing starship elsewhere in Trek Tech that led to this question) before the spaceframe aged out, with very few newbuilds of Con-re. Likewise, though there were probably a few earlier ships shaped like the Mirandas that were refitted into the Miranda-class between ST1 and ST2, the overwhelming majority of Mirandas extant in modern Trek times are newbuilds occurring from the 2270s into the 2330s or thereabouts, as opposed to refits of existing pre-Miranda ships...otherwise, the class would probably be referred to as Miranda-refit-class instead of just Miranda. I think the likely studio explanation of this is that they wanted more focus on the Galaxy-class and not on the Constitution-refit and thus didn't necessarily want to show a Galaxy next to a Con-re during the airing of TNG, but I don't really understand why the powers-that-be would worry about something petty like that; additionally, there were probably tons of Miranda-class models available for use. But it stands to reason that there's significantly better explanations, both in terms of show-making as well as in-universe. Thoughts, folks?