Most Helpful Girl
I think it's more of a stereotypical ideology pushed by the media. There are some women who fall prey to it acting on this expectation. I don't have that many pairs, and yes I do like shoes but women having more pairs than men is because we need more shoes than men do.
We have plenty dress codes to live by, different fashions for each seasons, sneakers and heels won't cover it all. When I was a teen I had plenty shoes because I was experimenting with looks, not all girls are like that so not all will collect pairs.
Over all I don't think I have a shoes obsession, but a need for shoes when I dress up, nowadays I dress like a soccer mom, so I am always casual with little need for anything besides flats.
Most Helpful Guy
Many women (and men) thinks shoes are important like how they thinks rest of the outfit is important. It's about aesthetic. People who finds aesthetic important finds both shoes, pants, shirt/t-shirt/sweater etc. important and wants the whole outfit to match to make it look good. If something don't match regardless if it's shoes or something else it's easy to notice and don't look good. People wants to look good.
A theory says women are often more interested in aesthetic which explains why fashion, interior etc. is important for many of them simply because they were gathers in the past while men were hunters. Colors and how things looked like mattered to be able to distinguish the food and to know which one were eatable. Therefor it's more common for women to be interested in both colors, things matching, things looking right and shopping than men. The theory says men wants to just do their business quick and then go home coming from that time when men hunted an animal and were finished after that.
Here the shoes is matching the outfit (In my opinion):
This picture shows why shoes is a big deal: