Why is tourist industry important to local people that live in the same island/state?

Answer 1

Money.

If you have tourists, you have hotels which employ people, usually locals; you also have B&Bs, which bring money to the local community. Food and supplies have to be bought somewhere - often from local suppliers. And tourists spend money when they go out, on meals, drinks, souveniers. Then there's the "tourist attraction" which generally charges an entrance fee - again, providing local employment.

Answer 2

In a word, taxes. In a couple additional words, pay check.

Think what all you're paying taxes on and for. Your home, your car, your water, schools, emergency services (police, fire, ambulance, etc.), libraries, roads, tourism. Yep, you're taxes even go to pay for the tourist industry. But the tourist industry can also help lower your taxes even if you don't see it by bringing in income into your town/island/state if it is succesful. Your taxes may be high, but think of how much higher it is if there is virtually no buisness (and tourism is a buisness) to help shoulder the burden.

Then there is the pay check. A succesful tourist industry opens more jobs for folks. It doesn't mean everyone is going to be a part of the industry, or that there's going to be people without jobs. But the more opportunity there is to get a pay check, even for just one season, the better off you may be.

Heck, when I go to the beach in the summer or a local fair in the fall, there are folks who are opening their own yards for parking and charging tourists and fair goers to park there. So that's another example of folks using tourism to make some money.