Technical question about self-cleaning ovens & high temp cooking

My stove is a ceramic/glass-top Kenmore convection, got it last year.

I just ran the self-clean feature as it was getting a little smoky during heating (just from dripped cheese and all the other crap over the last few months).

Self-cleaning ovens crank up to 900 degrees to burn the junk into ash. I don't know how hot mine gets but I'm guessing it's close.

My question is, if the oven is capable of hitting 900 degrees, then when doing regular cooking why am I limited to (usually) 500 degrees? Lots of people would like to make things like pizza in high-temp ovens, which they don't have at home, and yet the oven is obviously capable of running at a high temp for hours, so why isn't this an option? Are there average-price-range home ovens (under $1000) that allow you to do this?

My oven is totally locked until it cools down.

As far as a pizza oven, did you try googling? I know I've seen some at stores that are labeled 'pizza oven'. They look like table top things to me. I've never paid much attention to them, though, so have no idea if they're any good. I would sort of doubt it, though.

and it can't be a fire thing if it takes 3 hours to clean. I rarely run my oven for three hours in a row anyway. If it can do 3 hrs at 900 degrees, I think it'd have to have a certain degree of safety.

Part of the answer might be cookware - I don't know how many cooking vessels are rated for temps over 500.

That's my bitch about residential ovens, too. Not enough heat for some items .... like pizza.

My old oven was waaaaaay out of whack on its thermostat. As a result, it would easily get to 600, which made some great pizza. Alas, my new fancy-schmancy Kitchenaid is so precise it won't go one iota over 500.

GenTec last year was promoting a "low pressure" oven which accomplishes the same thing but by reducing pressure (at least they're pre-announcing it).

http://www.gentecinc.com/News.htm

Never heard of it myself. High-pressure, yes, but not low-pressure.