For that matter, they don't actually look that much like M-80's either other than the white driver cones. The "look-alike" comment is a bit of a stretch IMO.
As to the necessity for big drivers to provide adequate low-end , I think PMC for one has shown what can be done with smaller drivers and clever design in terms of extracting ample and high-quality bass from a speaker. My current PMC's have a small driver but plenty of bottom-end. The pair I'm waiting for utilize even smaller drivers and the low-end is as good or better. Big drivers have their own potential issues in terms of how the sound can be negatively affected.
Good design and good component quality are key to a successful outcome.
D.D.