I agree with everything you say but here is the reality. Brad Stevens is no longer a low level assistant, a scrappy coach or a fresh faced NBA Xs and Os guy. He is president of basketball operations for a $3.2B business and unlike his past, he has to do what he can to keep his biggest assets happy. As HRB states - and to be clear, there is zero sourced info out there that this is even remotely the case - if Tatum etc want Kidd, the Celtics are likely to hire him.
I don't think Jason Kidd is a good NBA coach, I have my doubts about him as a human being but if he is what the stars want, he is what they should get.
One other thing with these star driven hires is that they likely have an even shorter leash than an organization driven hire for obvious reasons. If these people fall down, management is likely to be quick to replace them, especially given the stakes. I can't see the C's sitting at, say, ~.500 into the deadline next year and being happy with their new coach.