I actually think that might be a good idea. I feel like a lot of people's privacy concerns would would be muted if browsers defaulted to private browsing.
Increasingly as I see things used to extract money from people, rather than build a better world, I wonder why not?
If a program defaults to writing in a hidden folder, probably what it's writing is not for my benefit.
If it's for my benefit, and I approve of it, it can go in /home/name/clear-folder or c:\users\name\documents\folder in an open and documented format with an open API.
If it's going in /home/name/.hidden/cache/dont-look or c:\users\name\appdata\company\{GUID} in an undocumented opaque blob without my knowledge, approval or explicit consent, it's much harder to argue that it's "for my benefit" and expect that I'd agree with that claim.
Turn everything opt-in and your computer reverts to being a disconnected 1990s less-useful computer.
Turn everything opt-out and your computer is increasingly tempting to be someone else's tool, a wringer for your life, a cash-extracting manipulation and abuse tool that does things you don't know about and didn't agree too, for other people's benefit. And we're not talking a defensible social good benefit like herd immunity to vaccines, either.
The real shock in these comments is not that "HN is amazed Google gathers this" or "HN is blazé about Google gathering this", it's "HN hasn't been able to log their own plain text search queries locally onto a NAS if they want to"
