Now i know why its harder and harder to find gameplay videos with no commentary on youtube. Turns out youtube considers gameplay videos you play yourself as reusing content, thus preventing the channel from monetization. This is quite annoying as If i want commentary, i'll watch reviews, not gameplay video with ramblings.
The weird thing is that this rules is not mentioned anywhere in youtube rules. Its only mentioned in replies from google's product expert on the google support forum. Even weirder, the official rules allows reused content as long as its not the majority of the videos in a channel, with no specifics of how many percentages is allowed (maybe a deliberate ambiguity?).
hmm, maybe there are more of these "hidden rules" in youtube.
Youtube also give special privilege/feature to big channels (e.g. they allows bungie to replace their video without updating the youtube url and video date).
Google Play Store also used to have "hidden rules". but they really improved over the years (in the clarity of the rules, and in placing the rules in easy-to-read places), and even provide specific feedbacks complete with screenshots. They are also laxer in "banning" developers. if an app is even found to have malware in it, they will unlist the app instead of banning the developer from monetization or something.