Agree that the UDMP and Ubiquiti gear is not for the casual user, but as a career IT guy I've learned to appreciate the "single pane of glass" when it comes to administration.
For years I managed multiple switches, firewalls, access points, IP camera stations, DHCP etc... each with their own management IP, credentials and interface.
Being able to manage wifi, lan, dhcp, firewall rules, vlans etc... all in once place, for me, is priceless. I wouldn't recommend it to everyone, but if your network and devices is already pretty complex, it's worth considering. I expect that folks on this forum probably fall within the magic quadrant.