I agree that concern about Win 10's telemetry is overblown. However...
USAFRet :
Lots of scary numbers, but no indication of what it was actually doing.
Nobody (well, nobody outside Microsoft) knows what it's actually doing because Microsoft encrypts the telemetry. They've refused to even say what data they're transmitting back despite calls from privacy advocates to reveal it.
1) The assumption is thus that it's private info that people wouldn't want Microsoft knowing, like what programs you run, how often you run them, what you do with them, etc. If it were stuff like what's causing Windows crashes, people would understand that it's feedback to improve the product. And Microsoft could just state that that's the data they're collecting and this issue would blow over. The fact that they refuse to say makes people assume the worst.
2) Making Win 10 a free upgrade (you had to pay for all past upgrades) raises suspicion that Microsoft is making money off Win 10 by selling your personal usage data to advertisers. The alternative is to believe that Microsoft made it a free upgrade as a goodwill gesture. Something most people find difficult to believe.
3) A lot of this telemetry is missing from the Enterprise version of Windows 10. Obviously they're collecting some data that would upset their corporate clients if they ever found out. So it would probably upset their individual users too, except the individual users don't have enough negotiating clout to get the telemetry removed.
I've been telling people to run the Spybot tool you linked earlier. And for good measure I've blocked the Microsoft telemetry IPs on my router. A lot of the data they're collecting is probably innocent product-improvement data. But I'm not taking any chances.