>why does a bookstore deserve money due to the arbitrary coincidence of its zip code matching your own?

I think it's because indie bookstores usually offer something additional to their communities!

For example, the indie I work for has the only free public restroom in the shopping area (we believe it's a human right), hosts free in-store events with authors, promotes locally self-published authors, drives authors to schools for in-classroom experiences for kids, hosts a holiday book drive to replenish our local school libraries, and sponsors events across the community!

Yes, we sell books to the people in our community, but we also try to lift up our community. I hope that makes sense.