A single Rekordbox database seems arbitrary

Dear Pioneer DJ,

I recently had the misfortune of having to reanalyze my entire collection for 75k tracks. All of the BPM information is stored in the meta data for the track why not use the BPM that is already in the track. Why go through so much trouble to obfuscate user data. 

Why only a single collection. why can I not create as many databases/collection as I choose. What if Microsoft Excel or Microsoft Access allow for only a single database. The data belongs to the end user allow for the user to create as many databases/collection as they choose. In my case, I would be able to store certain kinds of music in a smaller database/collection. I want to be able to click on the File menu and select Create Database or Open Database. 

Thank you.