When the Enterprise was designed in 1975 for the movie there was no design lineage for any of the ships other than the original series designs. So the new designs would have been state of the art at the time. In the seventies the straight edge and wedge wereI think the problem with the design is that it just doesn't have enough 'common design' elements with the 'past' to work in the context of "Trek that we knew".
I suspect that if one rounded the engineering hull some and gave it warp nacelles somewhat in keeping with TOS or even 'as shown' TMP design, and balanced out the different masses (Saucer,
Engineering and Nacelles) better we would have fallen in love with it.I know many people do not like this design but I am going to have a go at it. I built one around 25 years ago, pretty much a copy of the design for "Planet Of The Titans" but I was never really happy with it. I altered the model a few years later but again was not pleased with the design so I scrapped it. With Discovery using the McQuarrie design as inspiration I have decided to have another go at it, adding my own ideas that I used on my rework of the original that I built all those years ago. The one thing that bugged me was the primary hull, it had little or no resemblance to any Federation design so that is where I am starting with this model.
I am going to use flat surfaces to make up the primary hull, similar to how McQuarrie rendered the secondary hull, a loose interpretation of the constitution class hull:
I know this thing will be fugly, but hopefully in a good way.
And of course an argument could be made that the changes I suggest above are exactly what resulted in the 1701-D. Except that kinda goofy oval saucer.