If the designs are altered even one iota, then to the purist they are no longer the 60's designs. Just for starters, if you are going to make them look "more realistic", in the sense of looking like they are made out of metal and space-age plastic, or plasteel, or whatever, instead of painted wood, then they are really no longer the 60's designs. Having seen remastered The Menagerie on the big screen, I can tell you that when seen on the big screen, the TOS sets look like they were made out of wood.
The JJTrek producers looked at a set design that was closer to the original. Abrams concluded that it looked "preposterous and small" which is about right.
They did throw the TOS fans a bone with the Kelvin bridge, which is actually a design I prefer not only to the Enterprise bridge in this film but to just about all the bridges designed for Trek movies and shows prior to this (but after the TOS bridge). As it is the Kelvin bridge is more than a bit bigger than the TOS bridge.
The closest thing to a successful update of the TOS bridge itself was the bridge as seen in ST 5 (not the awful rearrangement and nonsense of ST 6). I liked that one, but it's still dated now, and I'm certainly glad that Chambers and company threw all of that out and started over. As it is, the JJPrise bridge draws most of its inspiration from Jefferies' original design, with very little taken from the various elaborations that have been done since.