I'm no expert on the Trumpeter line; I've bought exactly three of the company's ships. I rate the 1/700 North Carolina and Saratoga extremely highly, and the 1/350 Fletcher-class destroyer quite a bit lower. (I don't think it's quite as bad as some Forum commentators do, but it certainly doesn't represent a step up from the Tamiya competition.)
In general, though, it looks to me like what we're talking about her is a near-universal phenomenon: manufacturers get better as they get more experienced. That applies to virtually all of them. The Tamiya 1/350 battleships, at the time of their release back in the late seventies, represented the state of the art or something close to it. Nowadays they look...well, respectable, but outclassed by most of the more recent competition. For that matter, when the Revell 1/535 Missouri was originally released, back in 1954, most modelers found its details pretty awe-inspiring. By modern standards, it's...well, never mind. (I really wish Revell would take it off the market - but that doesn't seem likely.)
Every company also makes occasional steps backward, as Trumpeter seems to have done with that Fletcher-class destroyer. But the good ones stay in business, due, at least in part, to the fact that they keep up with the standards of the time.
What makes Trumpeter remarkable, it seems to me, is the sheer mass of kits it's produced in a relatively short time. I don't remember when the first genuinely new Trumpeter ships (as opposed to those awful, toylike ripoffs from other manufacturers) appeared, but it seems like it wasn't much more than a decade ago. (Beware my notorious memory. At my age the years fly by.) In Revell's first decade, 1954-1964, it released, by my count (in the appendix to Dr. Graham's fine book on the subject) 36 ship kits. (That includes sailing ships - but not modified or unmodified reissues). I don't know how many Trumpeter's released, but it's surely quite a few more than that. The Trumpeter/Pit Road design and production people seem to be working at a record pace. For some duds to pop up under such circumstances is probably inevitable.
I certainly agree with the above comments about Dragon's ships. I have yet to encounter one that I'd call a "bad" kit - or even a mediocre one. But even that company has been getting better with time. (Remember that 1/350 Typhoon-class Soviet sub - with the retractable torpedoes? And compare the first Dragon 1/700 Essex-class carriers with the most recent ones.)
Bottom line: even the weakest new releases nowadays are light years ahead of what modelers regarded as "good kits" twenty or thirty years ago. This is indeed a great time to be a modern warship modeler.