It's not because it will sully the purity of their craft. It's because it's a hobby. Much in the same way amateur dramatics companies don't charge anything except to cover the cost of the hall and maybe a bit towards costumes and props. That's how pretty much all historical re-enactors work. It's a fun hobby people do in their spare time.
As for games, a good one (which is pretty fun to play once you get the hang of it) is
Mia, which people will like because it's the real life version of that game they play in one of the Pirates of the Caribbean movies. Similiarly any other form of
liars dice games, like Mexicali. They're good fun because you can put on pirate accents and be all "I call ye a liar ye scurvy dog!" and such. Also good are
Shut the box (if you don't want to buy a box, just use nine dominoes) and
Ship, Captain, and Crew, which is almost pure chance and very easy to learn. I find
Hazard, which was very popular at the time, to be a bit too complex (to say the least). As for cards, you could have
Three Card Brag (which is kind of an early form of poker) and good old Blackjack. I wouldn't really dip into more historical card games than that, as they have a tendency to be mind-numbingly complicated, and that's without the ones you play on tarot decks and shit.
As for drink, you could always make up some grog and bumbo for people to try (bumbo is pirate grog made from rum, water, sugar and nutmeg, and tastes a shitload better than royal navy grog). There are also more palatable modern cocktail versions of both drinks. Spiced rum, hot water and a dash of lime cordial makes a fairly serviceable modern grog that ain't too offensive, or you can just generally play around with rum based drinks.
