I think it is a worldwide trend. I mentionned NPD, MC and Hobby Consolas in Spain.
Our industry is getting more and more secretive, why ? who's behind it ? I think is a real subject real.
Information is valuable, so companies with said information would want some money for that value.
Its not some kind of deep conspirancy by Publishers that dont want you to know their game failed so the force trackers not to release data.
And again, its not "Our industry".
You are not entitled to anything at all.
Every part of the industry can decide for itself how much information they want to disclose, and there is nothing wrong with that.
People talking about "transparency" in game sales info are like the people talking about "consumer rights" when it comes to game pricing.
It has nothing to do with the thing you mention.
Transparency is required from governments, or from companies that have info that actually affects people.(aka VS with the Diesel stuff, or BP with the oil spills).
Nobody complaining here needs Game sales for anything, the only people who do need that kind of information are devs/publishers making games, and they can pay to get said info.