Virtualization hype cycle

I've got hundreds of megabytes of presentation files from suppliers offering products or services targeting some one or more areas of virtualization technology. They promise the sun and the stars and sometimes only end up delivering the moon. It's fun to bring up last year's promises in this year's briefing session!  Some companies actions live up to their words. Others change their vision with the changing tides of the market.

Why do otherwise smart IT-decision makers let suppliers get away with this? Here are some random thoughts on why that might be the case.

• The decision makers are too busy to really understand the product or service that is being offered and look at the offer through the filter of what they'd like the offering to do.
• There is no complete plan or architecture for the use of virtualization technology in the company.  The decisions are entirely product or supplier driven. This is like purchasing a sports car when a passenger van is really needed because the decision maker really likes the shiny red color.
• The decision maker didn't talk with others to determine best practices in the area of virtualization technology.

Can you think of other reasons?