We have an older unit - 1999 chassis with the 4 speed tranny. We regularly see 4000 rpm on the tach (ScanGaugeII as the early models were not equipped with a tach in the cluster), and a few times, a little higher. I don't believe I've ever run it over 4500.
We've been all over the mountains in the west; its rare that we drop below 40, but then again we are not towing and packing 18K combined. This year has the 285 hp V10 so we have less horses to do the job than your 2013.
As Golden_HVAC stated, the V10 has small cylinders with a short stroke - it takes a lot of rpms to get any power out of them. I like to refer to it as "10 little cylinders, running just as fast as they can..."
The population of the US in general was raised on big engines with large bores and long strokes. We are not used to running big engines at high rpms... "its just wrong" in so many folks minds.
Mash the petal, Have fun!
And to the person whose opinion on minimum speed laws, yes there are, but that is on flat/gentle grades - on steep grades, you'll encounter any number of large vehicles creeping along at 10-20mph, up and down, and it is to be expected. In fact, it is very desirable to limit the speed of a 120K lb truck to 20mph heading downhill! A motorhome at 10k to 20k is no exception.