Perception of handmade quality

The trouble with knitting a pair of socks for someone with feet five sizes bigger than your own is that progress is slow, and thus not much blog fodder.  She tried on the almost-completed sock Wednesday night.

"It fits!"

The look of pleased shock on her face was priceless.  It already blew her mind that her feet were measured for this pair, rather than just going off shoe size.

Sock recipient aside, I've met several times now the expectation that "handmade stuff sucks", and that bothers me.  People seem boggled by the concept of handmade quality.  My mother sewed clothes, knit sweaters, and cooked every day.  My Dad built all the kitchen units, two sturdy sheds, innumerable wooden objects, and the back half of the house.  Quality handmade stuff was all around.

So can we come up with a good comeback when a muggle says "wow, that looks like you bought it in a store!"  I know it's meant as a compliment, that it looks too good to be what they would consider handmade, but what do you say? "Thanks, but this is better than store bought"?  "You can't get this kind of thing in a store"?

What would you say?