1. Their credentials provide some legitimacy to this endeavor.
2. They get to do some interesting work.
Those are the positives for them I see.
Rather than abstaining they work on it and lend their names. I don't know whether they support what Apple is doing with the protocol or if they just like figuring out the possibilities. I don't think either is good in this case because I don't like the very first application of this PSI System. Maybe I'm being short sighted and jumping to conclusions all at once. I still don't like it.