"systems may not support direct 911 dialing, route 911 calls to the nearest 911 call center, or transmit accurate information on the caller’s location or call-back number."
Points #2 and 3 are what's critical here.
Does it need to be fixed? Yes! but its wrong to assume that V911 is broken at a wholesale level. The same issues face E911 as well. The entire location system (Long/Lat) does not work well when altitude is brought into play. Their are standards in place for VOIP systems to transmit their exact NETWORK location, but it rarely implemented.