Unfortunately, much of the anti-gentrification rant is of the same homey small -town (or "neighborhhod" as it is called in Baltimore) localism. These folks like their little niche with a corner mom-and-pop store and seldom notice that it is surrounded by a sea of dilapidated housing, lack of any services, reatil an durban decline in general. They will oppose almost every new development in their "neighborhood" - from a bus stop, to a new transit line, to a new retail outlet, etc. and will cry gentrification at any attempt to reverse the urban decline that surrounds their little island. Been there, done that and know that genre very well.
My main argument againts this kind of localism is that contributes to urban decline and makes US cities unlivable. I have the means to move to the burbs, but I live in the city (in the empowerment zone, to be sure) by choice - yet few other people in my position make that decision. Most of my colleagues (mostly liberal or progressive types) live in the burbs and would never consider moving to the city - mainly because of the dilapidation and lack of services. The "white flight" to the burbs destroyed the tax base in cities - and the chronic lack of funds contributes to deterioration, lack of services etc. It is a vicious circle.
The only way to revere that sad trend is to attract people back to the cities, and the only way to do it is throuh the dreaded "gentrification." Personally I do not like the new-age yuppies and would not befriend one, but I like them for their neighborhood effect, or externalities if you will. When the yuppies move int, theiy do not move to the burbs, their taxes go to the city, the retail outlets and service start coming back, new jobs are created and most folks benefit. It may not have the old homey small town feeling anymore - but that is a different story.
Most of the anti-gentrification, NIMBY campaigns I have witnessed had this anti-big city, anti-growth, small town homey feeling in them. Perhaps not everyone shared it, but many did. I think such efforts are hopelessly misguided, as they derail urban renewal.
Wojtek