New couches can be just as ugly.....How about Digital Ugly couch Hotties?

I think the "ugly" couch effect can also partially be traced to the fact that a lot of the women are young, so they could be:

(1) Couches that were bought for school (cheaply);
(2) Couches in their parent's basement, etc. (older); or
(3) Couples who are recently married/on their own and getting hand me down or thrift shop furniture.

You covered most occasions but you missed (3a) the "First Apartment - Futon phase" (ie before couch).