So why paint individual single family home owners with the same brush? This is not analagous to the condo situation.
I agree. But, the original poster asked why, and that's why.
There has been a lot of discussion about changing the law. I don't believe the answer is to just prohibit foreclosure -- a condo homeowner could just refuse to pay association dues and the association could only put a lien on the home. The lien couldn't be collected until the home is sold, and if the owner doesn't move for a long time, the association (and all the other owners) would be screwed.
I'll suggest that foreclosure is only allowed if association dues exceed some threshold -- either an absolute amount or a percentage of the assessed value of the home.