It shouldn't exactly come as a shock that the people who have to live in proximity to the results of such systems have more to say about the downsides than those who can just observe from their ivory tower and can look at some spreadsheet, do a little math and say things like "net positive" with a clear conscience. Even if you have very good results the former group is simply going to be much more aware of the tradeoffs than the latter who will at best only know second hand.