Is Your Product Knowldege an Asset or Liability?

There was recently an interesting post by John Mansour on the Austin PMM Forum (registration required) discussing whether Product Knowledge was an Asset or Liability to product managers.

The author makes several claims about how product knowledge is a liability:

"In a nutshell, the more product knowledge you have, the less product
management you're doing because your product knowledge gets you sucked
in to a plethora of non product management issues."

"Furthermore, too much product knowledge leads to micro management - the kiss of death for anyone in a leadership role."

"Detailed product knowledge = liability because you can't see the forest from the weeds."

"Detailed product knowledge = liability because it forces you more into 'how' features should work instead of 'what's needed and why' from a business perspective."

"The more you know about your product the more difficult it is to position its true value. "

I have to disagree with Mr Mansour that these are true liabilities, in the sense that the absence of product knowledge doesn't truly mitigate the liabilities. Good product management is fundamentally about good product management.

It's your job as a good product manager to avoid running down the ratholes that you could run down as a result of your product knowledge.