I know they were removed in the past due to about the same reason, but the NLR Zones are abused more then they aren't from what I've seen.
I have a few reasons why I dislike, and personally think why the NLR Zones should be removed.
1) If you are RDMed, this is only going to be an annoyance to you.
2) If you kill someone near where they live, or really about anywhere and they seek to kill you back - you've just given them a circle of invincibility. This is abused sooooo much.
3) CHIL vs HEAT wars, or really any gunfight will cause some un-intentional RDM, usually in a key area of the map. The victims? Welp, tough luck.
I'm sure some other people can think of a few more reasons, but this is just my opinion.