Nice post, Larry. I would like to add that there are so many more aspects to this scenario, ala Jeff Foxworthy style (my apologies for using the "he" pronoun in advance, of course I mean to include YLs, too):
If a ham is using his Heathkit radio from the 1950s...he might be a QRP station.
If a ham inherited some QRP equipment...he might be a QRP station.
If a ham soldered up a transceiver kit (Rockmite, Heathkit, KX1, etc.)...he might be a QRP station.
If a ham has a poor antenna or poor antenna options...he might be a QRP station.
If a ham can't afford a "Big Time Operator" rig and a Yagi atop a 100' Rohn tower...he might be a QRP station.
If a ham station is located in an area where QRO may interfere with monitoring instruments, such as in an assisted living facility, dorm, or apartment building...he might be a QRP station.
Finally, if a ham typically doesn't want to fish with sticks of dynamite, use a sledgehammer to drive a thumbtack, or call in a backhoe to plant a tulip bulb...he might be a QRP station.
There are so many reasons a station might be QRP, and while life may be too short for QRP, I would say life would really get boring if I had a nearly 100% guarantee that my QRO signal was being heard throughout the world all the time. I like a challenge. I know that I am not any less of a ham than someone with a kilowatt amp, and I don't mind that they are using that sort of equipment. I enjoy working strong stations, but I particularly enjoy working weak stations more. As a hobby, I enjoy making contact with someone who has taken the time to make their own antenna, perhaps assembled their own transmitter, maybe even a separate receiver, and is trying to make contact with affordable equipment. I would love to have the latest Elecraft, Yaesu, Kenwood, etc., but any contact I make with my KX1 and homebrew, inverted V antenna is much more rewarding to me than one I would make with QRO equipment.