for those wondering mint or ubuntu
 

Ive been reading comments for the past four weeks on ubuntu and mint. cinnimon desktop or unity desktop. theres all sorts of stuff being said. after trying both of them out myself 'AS A NEW COMER' I can say that if you have been brought up on macs do not go near mint cinnimon because it operates and looks just like windows. For a mac guy like me, windows makes absolutely no sense. I cant stand it. the unity desktop is much more mac intuitive. of course its different, its linux, but it is more intuitive to a mac guy. If you have been brought up on windows then you MUST use mint cinnimon because it will be a delight for you.

I love Ubuntu and the unity desktop because I'm an old mac guy!

It should be noted that Mint Mate, xfce, kde -- not just cinnamon, would also fit your observation as a mac user.

Another ubuntu/debian derivative with a mac look is pinguy os

Pinguy OS Video Review
https://www.youtube.com/watch?v=Tp41nT8oDME

You can change the look of so many of them, (maybe all, but I haven't tried all of them) that your observations/opinions, are only based on the default install.
I would object to the word must in your post however. I am not into Gnome/Cinnamon/Mate and use LXDE, because it is lightweight, but I adapted it to my preferences.
There was even a Linux distro (Pearos), that looked more Mac like, and I downloaded to play with, the week that the creator shut it down, after having a friend discuss getting a Mac (wondered what it would be like). I've heard talk that others are trying to bring it back/recreate it.