Had she died off quickly, her $750K trust fund would have all gone to him. I'd say that's a pretty big motive.
Of course, since Judge Greer allowed Felos to fire Terri's guardian ad litem and refused to appoint another, that basically opened the floodgates on Terri's trust fund even though she's still alive. And whenever she dies, the money goes to him with no audit to notice if anything was taken out prematurely.
Except for one teensy problem: if Michael Schiavo ever gives up guardianship, the new guardian would be duty-bound to conduct an audit of the funds. If anything turns up missing, Felos and Schiavo end up in jail.
So at this point, I'd say that money isn't the motive directly. More like hoping the trust fund--even if nearly empty--becomes unambigiously his before anyone conducts an audit.
I think her family doesn't want him to get a dime of it. They are distraught and want to strip him of everything in anger. They want to blame someone and he is the closest target.
Well, there is substantial evidence that Mr. Schindler has tried to treat his Wife-In-Name-Only quite miserably. If he's refused to actually fund rehabilative treatment with any of the $750K which was put in trust for that exact purpose, why should he deserve one penny of it? He already legitimately got $300K for loss of consortium.
He hasn't been found to have committed any crimes against her. Though some people think he strangled her. God will always have the last say and we all will face judgment someday.
All matters of fact related to Terri have to be decided by Judge Greer. The same Judge Greer who sees no possible conflict of interest between a husband who's waiting to marry another woamn, and a wife whose death would greatly benefit the husband.