It's an interesting analysis. But without knowing their goals, it is easy to come to the wrong conclusion. For example, it may be that WeChat aims to generate more quality content from select users? If that were true, then it makes sense for them to limit video creators. Anyway, I am speculating ... It could be quite true that they don't know how to innovate. MySpace faced the same issue.
Walkthechat, without saying too much, be careful with that site (and it's so-called data). Double-check any facts before you trust it.