> You make a 2000 hr bulb and it's half as a dim as a 1000 hr bulb, and so you're going to need 2 bulbs instead.

Dubious. Most people would not rewire a room in their house to install a new ceiling light because a new bulb was half as bright as the old, because the new bulb would probably still be adequately bright and the new light level is something they could adjust to (much easier than rewiring their ceiling.)

In other words, there isn't a linear relationship between bulb brightness and the number of bulbs people use. The number of bulbs people use is relatively unresponsive to bulb brightness because bulbs need fixtures and changing fixtures is a pain in the ass.