I think people harbour ill feeling because
a. we all know some of them (not all) are lazy spongers
b. Anybody that has to private rent is hacked off because of the difference in price (plus the social tenants have security and better upgrades)
c. lots of the houses are an eyesore - not necessarily the actual house itself but the outside. We have newbuild estates nearby and the social housing bit is an eyesore already(rubbish lying in front garden, bags of shit, unkempt gardens etc) and the houses only got built in last couple of years. So they are pulling the area down for everyone else. The builder has put these houses on the front of the estate nearest the busy road so we all have to look at them as we walk our dogs/drive by. The rest of the area is nice and well kept so that pisses me off.
I think it feels like salt in the wound so to speak (ie they get cheaper and secure housing in a newbuild nice area and can't even be arsed to look after it. Just makes it seem like they don't appreciate their good fortune.