Hmmm, perhaps the reason most flight schools don't have an LSA qualified aircraft is that they are told (by exclusion in your survey as an example) that Sport Pilots aren't worth training (implied) and don't go farther in their training (stated, but untrue).
Number of Sport Pilots trained without LSA compliant aircraft = zero.
Therefore no need to obtain such an aircraft for training, as there are zero students.
Or so your logic works.
What would be more interesting is to see completion rates for Sport Pilot students.
Btw, Sport Pilots are money making honey holes for schools and instructors due to the further training required for additional endorsements.
While a SP might get his permit in twenty-something hours, there's still the controlled airspace endorsement, tailwheel, above/below 87 kts endorsement, upset training, spin training, and yes, even aerobatics.
Not including those who opt to extend to a PPL due to change of mission requirements in flying.
My flight instructor is somewhat biased against Sport Pilot training - he's in the "it's a half measure" camp - but admits that he has been shocked at what a sound investment his little Champ has been, generating more cash than his beloved C172....and proving to be somewhat of a gateway drug for PPL training.