Call me a nit-picker, but the whole "we're shoving the technology of a modern battleship into the frame of a steam-powered gunship, and hey presto that gunship now outperforms our battleship" excuse doesn't sit right with me.
The Vesta isn't tagged as a Cruiser by STO (I know that last modifier sounds a little unnecessary, but when you look at the fleet layouts there are multiple ships across the entire Federation roster that should be cruisers, but in fact are classified as something else). And to be honest, there really isn't any story-based reason for the problem, Cryptic simply hasn't been able (to date) to create an effective 25th century offensive cruiser design.
On the first one: Yeah, I completely agree, but when you run a MMO and more than half of the player base screams for these older 'iconic' designs they've seen in the shows you somehow try to make it work. I personally could very much live without the Ambassador in game, but there are a lot of people that were asking for it for a looong time. Now imagine after all this time they waited for this ship, Cryptic finally makes it, but makes it meek that it is not competitive in end-game content? Can you imagine the reaction and feedback they'd recieve?
On the second one: I was just kidding in this part. I was joking about the Vesta, seen how it is a science ship that can carry fighters, mount dual cannons and fire phaser lance more powerfull than the Galaxy-X amongs other things. Don't think I mentioned her to be a crusier though.
And I was joking that the Federation had become more peacefull, not due to storyline, but because for. ex the Excelsior can outpower the Galaxy.
Mind me though, I don't believe that Cryptic has a problem designing ships, I actually think they're pretty good at it. But, once again, in a MMO environment sometimes they have to follow what their player base wants and all I could hear lately was: Wells! Wells! then right after "When is the Vesta comming? Vesta!", then came the Vesta and the players were "How about that Ambassador, finally?". Now I hear the New Orleans is the next popular demand
So yeah, basically it's our fault as players that they've focused on creating some older and cannon ships in game, rather their own new designs. And Cryptic knows how to make their own ship designs, just take a look at the KDF side for proof of that.
"Honor allows us to overcome our weaknesses, to swallow false pride and find common cause with our enemies against a greater foe, and to be worthy of the glory that we receive from our actions."