Problem is, most people aren't looking to replies, especially on game threads, for evaluations of game quality. They're looking for answers to questions they have regarding launching, modding, formatting or bugs. What people are saying in the replies doesn't matter much when it comes to deciding whether to download the thing unless there's an overwhelming majority echoing the same sentiment regarding how good/bad/mid it is.
Reviews are different. You expect not just to see a short reply there that's only tangentially useful if at all ("Alright game. Needs more ass."), but more along the lines of at least a paragraph of input on precisely why you should or shouldn't spend data to download the game, if not more. However, getting that out of people is tough if they're disinclined to provide that much, and I've seen multiple reviews even on Fuck95 where people just put down something short and pointless, then add on "text to fill out the character requirement." You stand to gain a lot more of those kinds of people posting reviews if you reward them with coins, diluting the review page and making it unlikely that people will care about reviews being posted, or even the raw star ratings the game's earned, since you wouldn't be sure those weren't put there just because someone felt like visiting the LC shop.
I'd rather reviews be posted rarely yet mean something when they are since the person thought the game was worth saying something about, than that the review sections of all games be clogged with effortless drivel meant to drive up coin earnings. The former can be useful. The latter, not so much.
