But it certainly seems from all the posts you do in fact hate your neighbors. Probably that explains why you dismiss neighborhoods in favor of market areas. I could speak to other observations, but all of us show our characteristics on this forum - good and bad. If you study how a member responds and how they have changed the character of their responses over (in some cases) many years, you will become somewhat enlightened. (By the way, there is nothing wrong with the anti-neighbor sentiment. The Germans have always been fond of ignoring neighbors and treating them like they never knew them - probably because they have for the most part been a relatively dense population and have learned the advantages of such a policy. But that should leave you wondering as to the importance of neighborhoods.)
This speaks to a larger problem of appraiser bias. Maybe we SHOULDN'T let appraisers define these areas - at least not without statistical justification. This is indeed a wide-open door for appraiser bias. Cluster analysis, regression over latitude/longitude and perhaps the use of established MLS areas would be best.
What I really see when looking at the areas I have appraised over the years is the gradual disappearance of what at one time were rather distinct neighborhoods. Population growth and change.
What I see are nodes and filaments with sometimes large in-between areas. It is often like peering into the nervous system of some animal - or studying intergalactic space via pictures from the Hubble Space telescope. At times we see tumors and other strange growths. Like, of all things, Golf Courses that push housing into different directions, - or shopping malls that seem to attract other businesses over time - and create commercial areas that just keep growing, at the same time impacting the nature of housing. E.g. The Serramonte Mall Shopping Center in Daly City.
The world changes - yet appraisal is run by idiots who can do no better than keep thinking in the same way, decade after decade.