Ok, the OP asked why women don't like to wear the same dress more than once and majority of these replies are people saying that they don't wear their dresses more than once or being quite rude about people who do only wear a dress once.
I am someone who will not wear a special occasion dress more than once. By special occasion I mean a dress that I have worn to a wedding, christening, xmas party, hen night- any event that has a large amount of photography because I buy expensive dresses to make a statement. I recently paid £200 for a ted baker dress and wore it to my cousins wedding. The dress looked perfect but I will not wear that dress again, this year at least. If I were to wear that dress the following month to the horse racing with the same people then it wouldn't be the statement it was originally. I have no issue with wearing the dress the following year but its still unlikely to happen.
There are 2 reasons why its unlikely to happen
a) im a shopaholic and probably buy a new dress at least once a month (and im talking £50+).
b) I have a constant intake of new dresses that ill just wear a new one rather than an old one from last year.
Im aware that only wearing a dress once is ridiculously and provided a) you were not photographed in the dress and b) you are out with different people, then I say yes, wear the dress again.
I have some dresses (either white or black evening dresses) that I will wear regularly on a Saturday night because you can dress black or white up in so many ways. a little harder to do with a pink floral dress.
For me, buying a new dress and dressing it up for a wedding to showcase how good it is, is all part of the fun of going to a wedding.
I don't think its fair to judge people based on how often they wear a dress. I am someone who pays a lot of money for clothes. Im currently wearing a ralph Lauren jumper and ted baker jeans but I do this because I like how expensive clothes feel. I don't like the fit or feel of primark but I do not judge people who wear it. Im aware that there is no need to not re-wear a dress but it really does depend on the occasion and company you share when you are wearing it. I do feel that if the dress receives a high amount of compliments then people have noticed it and i wont wear it again but if it was a flock and no one really commented then i will probably wear it again. Crazy logic but that is the reality of my wardrobe. People who don't wear dresses more than once probably do this for the same reason as me and that is because its already made its statement.
P.S. It tends to only be statement dresses that don't get worn again. Most people wouldn't recognise a simple dress being accessorised in a different way and people still assume its a different dress.