What baffles me is, if you leave a house FOR YEARS, why don't you hire a neighbour for upkeep? I mean every now and then a roof tile must come off in a storm that needs to be refitted, a house that you don't heat in winter starts to rot, etc. pp.

I can actually see that in a moderately short time span of 8 years a lot of decay can happen naturally after which 'hands-on' neighbours might have just not felt too bad to tear down the remains.