I found these motors on hobbyking. according to the description they have been designed for quadcopter use. link
I also know the motors for arducopter where also specifically designed for quads
So what makes a quad motor, a quad motor?
The one thing I can notice is the large diameter outrunner for increasing torque for directly driving propeller to create lift.
what else? what are all those poles for?
I don't really know the answer to your question (high pole count) but the thing I think is attractive about those motors is the built in prop saver and I also really like the low profile although i can't imagine it actually improves performance but it looks cool! :-)
ideal quad motor (imho)
short shaft (wont break or bent that fast)
no protruding shaft (possibility to mount two motors coaxially, ease of mounting)
low kv (better for heavy lift/big prop quads)
mount with possibility to attach the motor to 10mm/15mm square bars without drilling them twice (ease of setup, possibility to move the motor, strength)
and long cables (i really want a motor for less than 15usd with long cables at hobbyking)