Because journalism is not the way to solve this, and we all think that it will.
The way to solve it is for "investigators" to get access to said source code and give us an honest assessment. Get someone neutral, get NDAs in place, have them look at the source in an air-gapped clean room, anonymize DB access, etc etc.
Instead we go around in circles. Journalism at the end of the day then becomes "we got some info that points to X, but we have no proof, and we won't look for it. We'll just wait till someone, somewhere, at some point, who knows when, finds some proof and puts it out in the public, only then will we say it's conclusive. Until then, you all go nuts, especially the conspiracy theorists. Don't worry, we'll ride this gravy train and report on those nut jobs too!".
It's a mess, and I'm not at all surprised that conspiracy-theorists have a field day with it.
Hey, let's get a bounty up so that a whistle-blower from Google comes forward. Maybe Mozilla foundation can take some of that sweet sweet endowment they use for "Social Justice" and pony up to fund this investigative effort. After all they claim to be fighting for a free internet. I'd say this is a much better use of money than paying random DEI consultancies huge speaking fees.