From my perspective, that shouldn't be a problem. Ultimately (as a user) the point of the rating is for me to get stuff that I like -- so it's all relative to m

From my perspective, that shouldn't be a problem. Ultimately (as a user) the point of the rating is for me to get stuff that I like -- so it's all relative to me, regardless of individual rating differences. Now, I realize that's almost certainly not the level of individualization offered by their ranking algorithm (I'm convinced there's way more of a "groupthink" dynamic), but that's partly my point: if your ratings and recommendation system isn't capable of supporting individual differences, then your algorithm is broken. If you have a complex problem (personalized recommendations absolutely are complicated) then you shouldn't fix a broken algorithm (Netflix recommendations are, at least for me, a bit meh) by simplifying the inputs (switching from stars to up/down). You should fix the broken algorithm, by creating a better algorithm. I realize it isn't that simple, particularly for a publicly-traded company whose stock price would absolutely be influenced by a decision to scrap part of their core technology, but from my perspective as a user, this is going to hurt my experience with the product.