I would agree with PR-21. Bare floor brushes aren't nearly as wide as power nozzles, they don't have the base support to stand openly. They have to either park onto the canister such as available on many modern units to include Miele, Sebo, Hoover Windtunnel Anniversary, Royal Lexon SR30020 and others. Or you can lean it on a wall or lay it down on suction unit while not in use.
All are angled with neck that rotates side to side but not up and down. Therefore neck is angled so that bristles on front and back will be at correct cleaning angle on floor for proper cleaning while in user operating position.
I hope this is helpful!! If you were thinking of something different from the direction I've skewed by your post, please let me know. I'm a canister vacuum lover and 90% of the time always use bare floor brush for hard floors.