Empty house on the street

Where I live there always seems to be a house up for sale.  There has been several times where people have simply moved on and left a house which seems odd to me.  We had a good streak going where I think every house on the block was occupied for like a year.  But now we have another house up for sale just two doors down from me.  The owners apparently left it.  I have looked up the home and it is modestly priced.  From the outside it looks in good shape.  A long drive-way, nice windows, and a good roof.  The people there were a little too active for my tastes.  They and their friends were always zipping down the street with their modified cars.  They had a yippy dog which I do not miss.  I prefer a quiet neighborhood where people are conscientious.

I just find it bizarre that the houses here have such turn-over.  My guess would have been that people would stay for longer periods and not just up and leave.