First of all, the stereotype of bingo-playing Catholics is really overblown. The vast majority of parishes don’t even have a bingo night. Second, gambling is not in and of itself wrong. Read your Bible and you will not find gambling condemned anywhere in it.
The average gambler loses money, but the process is entertaining, so what gambling amounts to is paying money to be entertained, and there is nothing wrong with that.
Gambling becomes sinful only when one pays too much money for the entertainment. A person in a casino spending thousands of dollars that his family needs is committing a sin, and the Church is very firm about this (Catechism of the Catholic Church 2413). It would likewise be sinful for a person to spend thousands of dollars his family needed on other forms of entertainment, too, like limited edition books, movies, collector’s items, or whatever.
However, if you can afford it, there is nothing wrong with spending a few dollars for an evening of entertainment, whether it is bingo, the movies, or something else. In fact, spending a few dollars on an evening playing bingo in a church basement with a bunch of fellow Christians is probably a more wholesome activity than spending the same amount of money going to see a typical movie–or for that matter staying home and watching TV for free.