Rebooting equipment means interruption at some customers. Especially if you're a business customer running VPN tunnels to different departments, having the ISP to reboot is equipment now and then is annoying.
I personally only reboot if it's required. I'm glad if stuff is running days after days after da....
Just had a look at a customer radio. It has been running for 240 days. In other words it has been running since it was installed
If you need to reboot, better use some time to find out why reboot is needed.
Before Chris came with the WISP switch I had to reboot my TOUGHswitches as they slowed down performance. So rebooting is often a required in a broken system, not a working system in my opinion...