You would have thought it was in Google's interests to do this. If the organic search tended to be full of the reviews (and if I am searching for a product I am

You would have thought it was in Google's interests to do this. If the organic search tended to be full of the reviews (and if I am searching for a product I am generally going to want to find out about it, especially user reviews, not where to buy it), then that incentivizes the online shops to buy paid ads. Everyone seems a winner if they do this, so it seems strange they may have gone in the other direction.