That's actually a quite common place to locate that stuff. It's gotta be somewhere, and it needs to be protected from the elements, and under the bed is relatively roomy and (hopefully) dry. My coach has it's load center, multiplex power switching system, and load management system under there. I've seen others with inverter, charger and transfer switch as well.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL