Personally, I'm less concerned about privacy of DNS queries than the loss of control and need to have another centralised third-party in the process.
Mozilla I don't understand. The most likely explanation appears to be that they are still in a catch-up-to-Chrome mindset, which is a disservice to themselves and their community.
DNS queries should be encrypted. Centralization-by-default is not the answer and people should look more closely at the incentives in play by those pushing the DoH standard. I appreciate the efforts of e.g. OpenBSD to prevent this side-channel leakage of user data to private corporations: https://undeadly.org/cgi?action=article;sid=20190911113856
Ideally one could change to any range of DoH resolvers - right now there's 3 or so.
Mozilla also send tons of users data to Google, and, probably, gets money/better contracts/other benefits.
Proof: https://twitter.com/jonathansampson/status/11658588961766604...
As far as I'm concerned, Google are only interested in DoH so far as prohibiting DNS level adblocking within their walled gardens.
cloudflare DOH fortunately uses it own domain for dns, so you can block it at firewall level.
Google could be evil and make resolver "google.com", so you would have to block whole google.
I was talking to a few people, of creating a list of all public doh servers, so we could all use it on our firewalls to block them.