The chief problem with the idea of NIMBY is that it is not really the concerned party's back yard. A more accurate term for the concept might be NIMNBY (Not In My Neighbors' Back Yard).
NIMBY is an affront to the concept of property rights. But, some say, the concerned party has the legitimate concern that development on a neighboring property will negatively impact the value of their own property. While an understandable concern to have, it does not justify the prevention of allowing the neighbor to develop on their rightfully owned property; just as company A should not be allowed to prevent company B from creating widgets because the extra competition will impact company A's bottom line.
NIMBY is an affront to the concept of property rights. But, some say, the concerned party has the legitimate concern that development on a neighboring property will negatively impact the value of their own property. While an understandable concern to have, it does not justify the prevention of allowing the neighbor to develop on their rightfully owned property; just as company A should not be allowed to prevent company B from creating widgets because the extra competition will impact company A's bottom line.