I heard a recent interview from one of the Panasonic top Dogs, and he expressed that he thought folk DIY developing firmware was interesting and exciting and viewed it positively, however they could never warranty issues arising from it.
So I suspect Canon feels much the same way, without ever officially admitting, they value the ML effort, but cant be seen to warranty one iota of it. Let's put it this way, canon loves to brag about how many motion pictures
a canon DSLR has been used. And when you read the interviews you start to realize that ML is one of the key reasons. So ML is actually adding prestige, respect, and notoriety to Canon DSLRs, which is way more than
their sensor development team has been earning. So the extra publicity also adds loyalists who like FLYs on a flypaper, once they have sunk a few grand in glass become stuck. JMHO.