I'm seeing similar things everywhere. I stood in line for a food truck a couple years ago that offered a promotion "$2 off your order if you show us your 5-star review of our truck on [site]." Obviously, you have to do this before you even order your food so I was intensely put-off by this. I gave them a 5-star review with no comment, received my discount, then after I tried the food I edited the review to 1-star wit…
Goodhart's Law: “When a measure becomes a target, it ceases to be a good measure.”
Luckily Amazon will take back anything and they are eating massive return costs from me for not having working, non-gamed reviews.