They have twice (that I'm aware of) tried rebranding as an advertising company. They are funded by Google (though not _necessarily_ influenced by them). There was an article in LWN by them about (in part) how they can't get enough information about users of Thunderbird so they were suggesting telemetry should be enabled by default and opt out instead of opt in because most people won't opt out.

I think they get a lot of credit because they aren't Google and not enough push back