I would like to see decent proof that they know what they are talking about.
TBH, I would not be surprised if Amazon thinks I rarely read at all -- I have not been doing a very good job of connecting according to their schedule, I strip the EndActions and rarely go past the badly-estimated last words, so I hope that isn't how they track it

and I often finish books while offline and then shuffle them off my Kindle.
Since it is all managed via calibre and a couple annotations-managing scripts, I find that my main reason to actually connect is in order to download new purchases.
I have a nagging suspicion that I am not the only heavy reader who acts this way...
I know some people even convert all their books first, even if purchased from their vendor's storefront anyway -- so they wouldn't show p as the same book!