The common officialist argument, for whatever it's worth, is that publishing the real values would induce panic and further inflation. Basically, they claim that it would be irresponsible to disclose the real values.
Short term this might work, but long-term (year or more) it becomes useless.
http://en.wikipedia.org/wiki/Rational_expectations
So, one way to diminish the crippling effects of inflation is to lie and say there is none. Of course, as you say, in the long run you'll get hammered, as people's expectations fly out of whack and they are required to guestimate future rates of inflation.
http://www.npr.org/blogs/money/2010/10/04/130329523/how-fake...