I've heard this phrase a lot. I last heard it on a radio show in the US I was doing where we talking about the digital distribution of music. Mine host was lamenting the inability of the record labels to distribute music on the Internet, particularly when it had such cost savings for them.
"They just don't get IT!", he said.
You hear this a lot in "blogosphere", particularly when people fail to understand the magic of the "blogosphere".
"They just don't get IT!"
What's the "IT"? Well, it doesn't really matter.