How overrated is oven temp??

I've seen people get real anal over cooking weed in the oven.  Well I've been cooking all my life and using higher temps isn't that bad.  Say you are cooking some weed oil at 400F.  Now this is an extreme, but still it works.  Just b/c the oven is on at 400f doens't mean your weed oil is at that temp.  Pizzas cook at a real high temp, usually 500F or higher.  Well guess what, does that pizza ever get burned?  NO!  Its b/c that the pizza never actually is at the temp of what the oven is on.  It is raw when put in the oven, and has to heat up (or cook) to reach its doneness, which is never 300F or higher.  If the 500F + temp would ruin the pizza, then why isnt the middle of the pizza burnt?  It isn't burnt b/c the temp in the middle is way way lower than the oven. 
 
Same applies with cook weed in stuff.  Say you make brownies at a temp of 350F.  Well the brownies are done when most of the liquid is evaporated, and this never reaches above 220F.  Hell the internal temp for crusty bread is around 212f, and they usually use a higher temp than brownies. 
 
So oven temp is overrated, especially when you factor in that the inside of whatever you are baking never reaches the temp that the oven is on.  I roast vegetables at around 425F or so, and they never burn, and its b/c the vegetables never reach the temp of the oven. 
 
So dont get so stress out about the oven temps, just bake and get baked!!