I reboot my hub manually when I have problems, if I don't have any problem I don't see the need to reboot it. It's not like it likely to die if you leave it alone for 2 weeks.
The reason why we always say reboot first, ask for support later, is that it forces a re connection to the CMTS which may fix a lot of problems.
Rebooting unnecessarily may cause problems too, such as if it's in the middle of a software update.