tech200, I am quite sure that the MMs and IIs have no relationship at all, unless illegal ones. The SEC monitors that also.
The MM has everything to gain by trades. They pay a BIG (1 Milj$+) fee to be allowed as MM. They get commissions on every single trade. They don't care where the PPS goes up or down.
Would the PPS have been higher if there would have been more liquidity (="had it not been for all these IIs buying in with the MMs") ?
IMO, yes, because IIs typically allow their shares to be lended at approx. 0,33% yearly fee. That keeps legal overnight shorting alive. And short trading pushes back on the PPS if skillfully done (=close position in high sell liquidity).
AIMO