I have several hypotheses:
- Some people don't even think about it. Many probably don't see there is a political aspect to browsers. What harm is there in suggesting something? It's not even clear that it is an ad, they are not going to buy Edge, it's free. What's more, they may only know one OS and take whatever they are provided with as is without any critical look. They probably trust their computer (yeah, and this is scary, but since the system shows this ad, some will probably take it as good advice to follow, and Microsoft is very wrong doing this because they know it).
- Some are accustomed to ads. Some may even ignore them without knowing. Some people probably notice but don't care. By the way, why shouldn't a computer display ads in its UI if you are not against the idea of ads? (I personnally hate ads)
- Some probably think it's not okay, but possibly forget about it and get on with their lives anyway, and/or don't tell anybody about it, so we would not even know whether people think it is ok.
People have been accepting ads in paid products/services for generations. Cable TV channels have always had them, as have newspapers/magazines. Most movie theater chains run their own ads these days (not just trailers).
It's easy to see why Microsoft is dipping their toes into this - sadly, consumers don't seem to mind so much
Hell, after years of having used *nix as my primary OS on my personal development laptop, I switched it to a surface pro 6 last year. I’m fairly certain these things is going to push me back to a Linux laptop.