I had the same thought when I read this. I used to turn off my computer every night, until I switched from Windows (98) to Linux. In grad school, my roommate and I had uptime contests with our Linux boxes, which he won with something like 6 months of uptime. The most common causes of lost uptime were electrical power outages and moving apartments.
Now, like you, I mainly run OS X, but it's on a laptop, which wreaks havoc with my uptime. Ah, well. I guess you can't have it all.
I don't reboot - but I do close the lid to let it sleep. My main reason for not rebooting is I generally have 100 things open at any time and that 'state' is important.
As memory and bulk storage become faster and faster and gain more and more capacity I think that the idea of losing application state just because your PC shut off will become a horror story to tell our children. Eventually it will become one large memory space backed by a variety of local and network stores.
I do the same thing, but even with sleep sometimes my machine gets hosed (the technical term) and requires a reboot. That never happened with my old Linux box.
I'd turn it around: Why would you turn your computer off if you don't have to? The power consumption is roughly $0/year, and by keeping it on you don't have to resurrect your editors, terminal windows, and browsers every morning.
Now, like you, I mainly run OS X, but it's on a laptop, which wreaks havoc with my uptime. Ah, well. I guess you can't have it all.