In my particular situation, space for an enclosure was very limited. I went with 8" subs because of the mounting depth and enclosure requirements. I could have fit 4, but the enclosure would not have sounded like I wanted it to. I realize that my amp is capable of more, but it is not needed. My subs get approximately 250 watts each continous, which is plenty. I should not have to worry about fluctuations because my sub amp is 1 ohm stable. It is well within its abilities.
By the way, I completely agree with you. And thanks for posting an intelligent response and not bagging on my "weak" system.