Negotiating a Sale Shouldn't Take Four Months

In today's market I think too many real estate professionals have gotten into a pattern of allowing negotiations to drag out for too long.  I am currently in month four of negotiating a contract and I really feel this industry has reached a new low.

Banks have historically been slow to respond to offers.  Perhaps because of the high volume of foreclosures and short sales, we have changed our expectations of how long sellers should take to respond.  But I think we should go back to the "Time is of the Essence" clause and hold our industry to the standard.

Yesterday I was told by an agent that they hadn't been granted enough time to consider the offer.  What part of four months isn't enough time?  I only changed the price and the closing date and when I gave a deadline for a response I was basically laughed at.  Arrogantly the seller said he'd get to me by Monday.  I don't understand that and I don't understand the agents who would pass that on the me.  But maybe I'm just old fashioned?  I have represented quite a few banks and short sales in the past two years, so maybe this is just karma.