Many synagogues have trouble getting a minyan. This can be a problem for someone that needs to say kadish.
Sometimes I'll attend minyan just so that my shul can get 10 people (a minyan).
My shul, with 800 families, and it's hard to get 10 some evenings.
The orthodox insist on 10 men. Many Conservative shuls will also count woman in the minyan.
(This is a
'hot' topic in some circles).