I think one of the major things that people overlook is who runs or rather owns these websites. Rotten Tomatoes is owned by Fandango, which is majority owned by NBC Universal (Comcast) and partly owned by Time Warner (Warner Bros). Similar site, Metacritic, is owned by CBS, which is more or less owned by Viacom.

It is certainly possible that they have autonomy from their parent owners, but if their review scores have a measurable influence over ticket sales for films with >$200 million budgets, I wouldn't be surprised that there are some meddling with the average "scores" that they give out. I would even argue they should do it, for profit.

There was a good, short article on fivethirtyeight on why USA has dominated woman's soccer in recent times

http://fivethirtyeight.com/datalab/why-is-the-u-s-so-good-at-womens-soccer/