Northwood even puts a 1-1/4" receiver welded to their bumpers. That should be good for 350lbs of rack and bikes. Not all bumpers and the way they're welded to the frame are equal. My 5'er came with the spare on the rear bumper.
JMO but it seems as though the story of a few bikes that that fell off that were seen by a couple people has been blown out of proportion. Put several bikes on a cheap wiggly bike rack that's mounted to a poorly attached bumper and yes you will have trouble. Put several bikes on a well made bike rack that's attached to a solid well attached bumper and you'll have no issues.
Lots of arm chair engineers that haven't done much in the way of building anything seem to have a better opinion. The guys that have hands on knowledge of construction have enough common sense to figure out what will or won't work.