I've never had a problem with this.
In the past I've refused to co-sign on loans or buy Multi-level products and services from friends and relatives...etc
However if someone is experiencing this issue they first of all need to take ownership for creating the problem. Saying "no" is your right!
Each of us gets to (choose) our own friends, lovers, and spouse.
We get to (choose) who we spend our time with!
Being a friend doesn't mean one has to say "yes" to everything.
If you lose a friend because you didn't give them money they weren't your friend to begin with. In order to be used (you) have to allow it.
Everyone is entitled to have their own boundaries & deal breakers.