People play at level cap far longer then they do getting to level cap. It takes about 75 hours of PvE to go from 1 to 51 on the Fed side. I agree there should be more lower-level ship choices but most people are only at a tier around 10-15 hours before moving on.
And if you really want, you can do it considerably faster than 75 hours. That's solo, no twinking. Just dinged a guy to 51 in under 2 days played. And that was with goofing off and a bit of a learning curve perfecting the route. Go go mission replay.
Anyway, me, I'd like to see a way to be able to use lower level ships at the higher levels. Something like a T3 cruiser being like a T5 cruiser, except with a universal ensign slot at the cost of having only 2 science and tactical consoles. If they set up something universal like that for each category (cruiser, science, escort fed side), then any ship T2 through T4 can be upgraded to very close to T5 standards. And that means they can introduce new lower tier ships and they'll still have value at the highest levels.
I like the look of the older ships better than the new ones. If Starfleet can update the Excess class and make it better than a Miranda, then they can update the other ships to current standards (aka T5) as well. Plus I like the idea of a wider variety of vessels hanging out, seeing some of this and some of that, rather than the same ships over and over.
I am just saying that middle rank players should get something new....thats all....
No one stays a mid-level player. If that changes (and it might be possible it does, there has been discussion on the ability to stop leveling), then the ship options at a certain level might be discused again, too.