Nice post OP. Just wanted to add some clarifying info from my own experiences with this issue for others who may find it....
I'm an IT consultant for small businesses in my area, so I've been getting a bunch of calls about QuickBooks since last thursday. Intuit has posted that the offending update is KB4074805 (which OP listed). I have been finding that update not installed on the computers I've seen with the issue. Instead, I've been finding the update is KB4073701. Personally, I would recommend removing either of these updates if you find them on your system.
Also, you shouldn't need to go to the extent that OP did and uninstall .NET 4.7 (or like I did the first time and run a system restore). Simply uninstalling the specific update should take care of the issue. To do this, open Windows Update (found in Control Panel or under All Programs in the Start menu), click on "Installed Updates" on the bottom of the left hand panel, and you should see a list of all installed updates. If it isn't already, sort it by install date (click on the "Installed On" column header) which should show you the most recent updates at the top of the list. The KB number is listed in parentheses at the end of the name. Look through your recent updates to see if you find either of the KB numbers bolded above. If you do, either select it and click Uninstall near the top of the window, or just right click it and click Uninstall from the context menu. From there, follow any on screen instructions, but it should just go from there. Might ask you for a restart, which you should do if it does.
You may also want to make sure to block the update from installing in the future. To do this, go back into Windows Update and check for new updates. Go into the list, and if you find one of those KB's noted above, right click on it and select "Hide Update". This should prevent it from being autoinstalled on you. Don't worry about having to undo this... when Microsoft pushes out a good version of the patch, you won't need to install this one first.
One final mention: I've only seen this on Windows 7 and Server 2008r2 machines. Windows 8 and 10 appear to be unaffected.