What you said is true, but your conclusion is completely wrong. To say simply, 'I did like macs but now I will not touch them or anything else Apple makes' is a crazy conclusion to make from something you misinterpreted.
The 'App Store' is an application installed on your OS X computer. This application downloads apps from Apple. This application only downloads apps to the Applications folder. So, therefore the APP STORE APPLICATION knows what you have installed and do not have installed to the APPLICATIONS FOLDER ONLY.
Try this: Purchase an app from the App Store. Now move it to another folder on the system. It still runs - there's no requirement for applications to reside in the Applications folder. Now the App Store Application thinks your purchased app is no longer installed on your system - even though it is, just somewhere else. This is all done inside the APPLICATION, with no data going to Apple. The only thing Apple knows about is that your Apple ID purchased the particular app. Apple has no clue whether it is actually installed on your system, and the App Store Application has no clue either - just whether or not it's where it put it in the first place.
Now tell me again how your conclusion makes any sense.