Why are the banks pricing homes too low?

My beef right now with the banks that they are giving consumers false numbers.  In fact, in order to so call WIN a home for your client you have to convince them that they should write their offer for about 20,000 to 40,000 over list price! As these false list prices do intice folks to make offers, it is very maddening that they also are now "sitting' on your offer. Even if you have had made a clean offer and your client is going over asking price they still are chosing yet someone elses all cash offer! Any advice for me?