[Reposted from another thread]
The short version is that it's a higher budget work and they don't want to stick to the "canon" of appearances because it's ridiculous to do so when the original Enterprise doors opened with a rope. But in the old days Trekkies used to speculate on these discrepancies and have FUN reconciling them rather than just get mad about them like:
Obviously, it's doing the writer's job for them but that's ALWAYS been the case. It's a game.
Holographic coms and not viewscreen
The more utilitarian Starfleet comes as a result of the ships needing to be easier to repair and less fragile after a horrifying war with the Klingons. As a result, they go to switches and piping which makes the ships much much easier to work as well as less bells and whistles but sturdier by far.
Warp capable shuttlecraft
Starfleet stopped making them because they realized it was an unnecessary luxury and encouraged people to take longer trips when they should stick closer to larger and better protected vessels.
Enterprise Delta on discovery
A hypothetical ship design which was eventually picked up by actual fans of the ship....or it's just an Easter egg.
Entire redesign of klingon ships (the Kingons them self I can just about live with)
The D7 is actually a depiction of its type rather than its model. D-1 for example could mean "Starfighter", D-4 could mean Frigate, and D7 could mean Dreadnought.
To me, it seems like there is absolutely no reason to set it in the time they have, especially if they wanted to play around with new tech (spore drive anyone).
Alternatively, this is the future of ENTERPRISE which is slightly different from The Original Series due to the events of First Contact and The Temporal Cold War. In this reality, the Earth lost 7 million people to the Xindi Attack and thus pressed its starship program much-much further and faster than in Kirk's time.
Why the Klingon redesign?
The Augment virus which created the ridgeless Klingons eventually mutated and created the "Ridged Klingons" who are to Klingons what neanderthals are stereotypically depicted as to us. Indeed, it may actually be deliberate as the Klingon's geneticists overdid the result to make them as less humanlike as possible.
The Blood Purity and ISIL elements of the new Klingons may be due to the fact they feel they've been "contaminated" by human blood.
Alternatively, not all Klingons are like and we're just seeing sub-equatorial Klingons.