Taken a bit out of context though, that thread is about selling PCs with unactivated windows, which is a violation of terms.
Nowhere does that explicitly apply to personal use, if MS didnt want it happening they would put a time window on it like they have with previous versions of windows.
Also, your comparison does not really make sense, since a busted window pane would impact the functionality of the space, unactivated windows is fully functional.
The house thing was meant to be a slight joke - I'm sorry the humour didn't make it through the internet intact.
Either way, it's against the terms MS have for you using the software. That topic's context isn't relevant as much as the part where they highlight this from the EULA / terms:
Depending on how you obtained the Windows software, this is a license agreement between (i) you and the device manufacturer or software installer that distributes the software with your device; or (ii) you and Microsoft Corporation (or, based on where you live or, if a business, where your principal place of business is located, one of its affiliates) if you acquired the software from a retailer.
....
This agreement describes your rights and the conditions upon which you may use the Windows software
....
5. Software and Activation. You are authorized to use this software only if you are properly licensed and the software has been properly activated with a genuine product key or by other authorized method. When you connect to the Internet while using the software, the software will automatically contact Microsoft or its affiliate to conduct activation to associate it with a certain device. You can also activate the software manually by Internet or telephone. In either case, transmission of certain information will occur, and Internet, telephone and SMS service charges may apply. During activation (or reactivation that may be triggered by changes to your device’s components), the software may determine that the installed instance of the software is counterfeit, improperly licensed or includes unauthorized changes. If activation fails, the software will attempt to repair itself by replacing any tampered Microsoft software with genuine Microsoft software. You may also receive reminders to obtain a proper license for the software. Successful activation does not confirm that the software is genuine or properly licensed. You may not bypass or circumvent activation. To help determine if your software is genuine and whether you are properly licensed, see (aka.ms/genuine). Certain updates, support, and other services might only be offered to users of genuine Microsoft software.
https://www.microsoft.com/en-us/Useterms/Retail/Windows/10/UseTerms_Retail_Windows_10_English.htm
I'm not saying you physically can't use Windows without it being activated. Just that it's against the terms for using the software. And that Microsoft do make that very clear.
That's there in black and white and not really open to interpretation.