The sets and designs of TOS are dated - they're 40 years old and they're stale. TNG is already looking old and dated too, IMO. That doesn't detract from their appeal, but this movie is targeted at a wider audience than just Trek fans, and that wider audience has been laughing at us for years - "hey, why does Picard walk around in his pyjamas?

" Making Trek that just caters to existing fans brings us drek like INS, NEM and ENT - and we already know they aren't going to do that any more so the only answer is update it. Or throw it away and forget it, but I'd rather they did the former than the latter.
The sets and ship designs have been modernised, just like they were for TMP. And don't start on about "refits" and "swappable bridges," because both of those are simply "canon" explanations for what they did - modernise the sets and the ship designs for a new audience. I can accept that some changes are probably more than what was required - particularly the bridge - but it's
their movie, and I can live with
their decisions.
I'm genuinely sad that some people feel so affronted by what we're getting, but the bottom line is that it's happened - we have a new ship, new sets, new actors.
Now, I'm going to go and watch a TOS DVD.