New video chat apps

it's 50/50 new messengers and sunsetting the old messengers

I don't think you meant this sarcastically but it's probably closer to reality than you think.

They certainly aren't paying full-time employees to go through tedious stuff like that. That's what contractors are for!

And on removing features from Google Maps.

Why? Nightski doesn't say whether they actually used the app.

.. responsibility? Google? I don't see how this would hurt their advertisers.

Responsibility for what, exactly? They don't have a responsibility to publish any particular review in the store. They're free to include/exclude/weight the data they receive to give you star ratings for apps in any way they'd like. Vote clumps like this one tend to make star ratings less trustworthy as a measure of the true quality of an app, so I'd expect an app store operator to discount them.