Different circles act differently. In grad school every student was stringy and would take and never return. After I worked in tech everyone was quite generous.
Funnily enough, I don't think it's a money issue - I think that people have adopted such a consumerist, transactional mindset, that they can't distinguish the difference of services provided to them by the system at the swipe of their credit cards and the things other people put effort into (who are under absolutely no obligation to do so).
It's the same transactional mindset view of 'what can you do for me' that's outlined in the top comment.
Which is a foolish way to view the world imo, as friendships are much more difficult to acquire than money, but it is what it is.
