Even if oven fires aren't likely, it's definitely weird that my microwave will beep every minute until you open the door just in case you forget you need to eat to live, and my oven will happily run for hours (days?) and doesn't seem to remind you about how you might be accidentally incinerating something, it seems like a beep every hour (with a button to mute it) wouldn't be unappreciated.

Although I guess if it's not a safety thing, the cost of the extra design might be more than I'd expect to save on my electric bill from the once a year or less I leave it on overnight by mistake.