Earlier quoted context omitted.
If #1 is true in terms of past behavior, then expecting this price point to change that is doubtful. In my experience, the reason no on upgrades is because they then inherit all the cruft from their old install. I'm not sure that upgrading will ever be popular with the Windows crows. #2 is also doubtful for the same reason. If users are faced with 900 versions of Windows to choose from while upgrading, they'll choose…
Correlation does not imply causality. The burden of proof is on the inclusive case. Windows upgrades allow fresh installs so that's rubbish.
It's a fact of Windows in the consumer market that upgrades just don't happen. Consumers almost always run their computers into the ground, then get the latest version of Windows when they purchase a new PC. This is something you stated in your post, yet you seem to think that MS will magically change this behaviour with this price point. I see no evidence to support that.
Additionally, the MS Store is almost a direct response to Apple's App Store on OSX.