As a mini-map, I guess it is ok. The transparent white-blue style combined with overly large icons is annoying and makes it less useful than it should be, but it is useful. I also tend to have it enlarged since it's too damn small when playing at 1920x1080 otherwise (wish they would let you scale the HUD elements yourself). So as I said, it does the job as a mini-map but that's not the main problem.
I happen to like the white and blue style, if it was more detailed I think it would be more of a hindrance than anything. I too play at 1080p and find it way too big when enlarged.
The big reason why it's useless is that enlarging it is crap. When I press m I want something more like this:
No argument here. We should be able to access the full (zoomed-in) map when not spawning. Not sure why they decided to exclude that, but for the most part I use the mini-map for situational awareness, and as far as that goes it does its job quite well.