Re: "It solves a problem that people have."
NetworkManager isn't something you should disable as of RHEL/CentOS 7, it's actually better (IMO) than Network in RHEL/CentOS 7. The reason most people hate NetworkManager was because of how terrible the implementation in RHEL/CentOS 6 was.
One of the reasons Network Manager is better in RHEL/CentOS 7 is that it gives separation between connection and device which (in my opinion at least) gives you far more power over your network configuration and more versatility all-round, but it does require a lot more learning for it but at least bash completion exists.