@PeteStan I'd say @PhilipDAth is correct and that the MR30H is first and foremost an AP, not a switch by any means, and the port profiles are all about extending SSIDs to wired interfaces, as well as having "wired only" SSIDs so you can configure all the same firewall rules, traffic shaping, splash page, etc on wired devices, as if they were associated wirelessly.
Just like configuring wireless on an MX-W appliance has its limitations compared to deploying full-blown APs... As an AP the MR30H just doesn't have the switching chipset or capacity for all those functions. I won't disagree that going from configuring switch ports to configuring port profiles is a bit jarring and certainly has some limitations compared to regular switch port settings, and perhaps the UI could be made a bit more intuitive or offer a few extra "i" bubbles to guide configuration.