It is not about being known in advance. It's to complain that a product is overpriced. People do this all the time, go look at reddit or HN or anywhere else complaining about inflated monthly costs, expensive SaaS, lamenting how Adobe is now a subscription.
I don't know what you're selling, but one of the best ways to get a shitty price review is if you lock any features behind IAP. To prevent this, sell a 2nd version with the feature already in there _with an app purchase price_, not IAP.
For required permissions, absolutely, I would complain and let people know, especially people that are not technically inclined, if something was demanding contacts or location or the ability to scan for BTLE when they don't need it and it's purely to satisfy a tracking or advertising SDK. 1 star, disgusting abusive behaviour.
They are helpful to me: these reviews tell me when a free app might be hiding payments behind IAP (Android's store does not list every possible IAP + their cost and description, iOS does, so on Android almost every app just has a $0.99-$99.99 listing), they tell me when an app is trying to potentially steal data, contacts, or similar, they tell me that there might be a similar product that is cheaper or actually free in the same niche.
I understand. I would not 1 star a paid app for $5 because I wanted it for $0.99, that's dumb (though think about how smart the average person is, and assume half of them are less than average, and they all have phones too).
Let's say a free app advertises "play online with friends and play by yourself" and is free to play, free to download. Then you finish wasting 2GB of your mobile data ($30+ in US) and create an account (monetized, spammed) and now you find out that a mandatory payment IAP is required to play multiplayer. That deserves 1 star and probably a report.
Unrelated: You also have the shitty-behaviour apps that are either legitimately good or bad, but pop up "RATE US 5 STARS" every other launch. I would like those permanently banned from the store forever.