Ads do really seem increasingly likely to transport some political/ideological content. Is this happening the customer's explicit request, or are agencies and/or their individual creatives surreptiously hitching a political/ideological ride at their customer's risk and expense?
Maybe Civil Society's empathy was exploited a bit too much, a bit too brazenly. If that's the reason, insisting the show must go on won't get you much empathy.
Mercury brings a bit more sanity to Prolog with its mode system. This is one of the key reasons why it runs fast and can be used to build big systems like Prince. That said, it _is_ a restriction on expressiveness of programs, and sometimes that makes it hard to do certain things. That's true of any type system.
There's still an interesting question about whether a different iteration on the mode system could capture more of the semantics of Prolog while still being useful, but so far nobody has done that research yet. It's more trendy to do FP research these days, so I'm expecting it could be a _long_ time before we get an answer, sadly.
The point of being GPL free is you don't need to release source code.
If you combine this with the other point of Fuchsia, hardcore security, the final combined result is that nobody can audit what Google is actually doing on "your" devices. And that's why.
Which is why I strongly suspect ad agency creatives did this on their own. Being in Brazil may have made them feel free from client scrutiny.