Sorry clouded my assertion - FR 541 is a rim designed for DH, which is perfect for an emtb, even though said emtb is being used for general trail riding. DT Swiss designed the FR 541 to be very similar to the HX 531 which they label as an ebike rim. There's method to it, it's not just...
Simple physics - stronger rims more resistance to damage. Obviously you don't need them but those of us who don't spend all our time on grade 2 flow trails certainly do...
Here's a good analysis of the FR541 by an actual professional wheelbuilder (which is NOT ebike specific BTW)...
I had a set of Duroc 40 on an Ibis HD4 and they didn't last long before splitting around the spoke nipples. Freehub also gave out. My HV2 on a Trek Rail have been very good and taken a real pounding - a full week's worth of bike park resulted in a few dings and I had to completely retension, but...