1) I didn't say that they are there for no reason, rather that there is no reason why there can't be a simple switch which turns everything off in an easily accessible way, or heck even having everything off by default. And no, Microsoft needs telemetry is not a reason when we're talking about user-friendliness/respect.
2) No, but you can get away from malicious defaults. Believe it or not, but there's OSs out there where the defaults are an actual recommendation from actual people. And again, same fallacy. Just because every OS has bugs, doesn't mean that it's ok for one OS to suddenly have more of them for no reason, or in this case more severe bugs, as with user-respecting defaults only the most hardcore Microsoft-fanboys would complain that their computer suddenly stopped sending telemetry to Microsoft.
3) Because we don't know the extent of the damage that this does. We don't know what is being sent, what is being stored, how long it's being stored. Could be that even the most privacy-friendly setting can still report you to the NSA and get you on some list. Could be that people have already disappeared, because they were on such a list at the NSA, without anyone knowing about it. The same stuff was going on for a good while at the Stasi before people noticed, and the Stasi was a bad joke in comparison to the NSA.
> You can switch for whatever reasons you want though. Are you actually a Windows user who is considering a switch?
No, I already switched with the Windows 10 + new ToS launch in expectation of something like this going down, although I also just got extremely lucky, as it wasn't my only reason at the time. This actually going down, though, certainly has cemented that decision. Why do you ask?