Its not that the new tennanats have a cheek for moving in (if they are oblivious to what went on, in which case the estate agent should rot in hell). It's that April Jones's family want the place demolished, local support will be totally behind them, (thousands of local people volunteered for a co-ordinated search of the surrounding countryside, one of my old friends was amongst them) there will be an extreme element amongst that group that will think they are doing the right thing by making the lives of whoever is unfortunate enough to move into that cottage absolute hell.
Of course not every house where a murder is commited can be knocked down and replaced by a memorial. Although everyone is supposed to be equal, this is clearly not the case. The murder of young people/young girls in particular allways evokes the strongest feelings, and this was a huge story for the local, national, maybe international media. If it had been some evil criminal psycopath who had been murdered then things would be totally different. In the eyes of the law Murder is Murder no matter who was killed, but its quite different in the eyes of the public how they react to different murders.
Btw Im not condoning bricking Bridger's ex home, i feel sorry for whoever is gonna be unfortunate/dumb/maybe just plain ghoulishly sick enough to live there. Their lives are gonna be made hell.