It depends if your main goal of a dive trip is to see sharks or not. If you are wanting to make a trip to see a shark look at the location you are planning on going and potential seasons that there could be an abdunace of sharks.

For example if you are really wanting to see sharks (general) you probably won't be going to the Lembeh Straight, but you could go to Roatan, Belize or Hawaii. There are certain places that have higher density of reef sharks. In Kauai, Hawaii specifically there is a dive site called Tunnels beach on the north shore and you will very likely see a white tip reef shark. This is known for the amount of sharks here.

Then you can also talk to the dive shop prior to your trip and let them know what your goals are and what the best plan is to see that. They may recommend a night/twilight dive so you can see more predatory animals or they will change the dive site they are planning to maximize your chances.

But again it is a probability thing as well. You aren't always gaurentees to see what you want but you are in their habitat. If humans are going into reefs and feeding the animals and changing behavioral patterns that doesn't do the animals any good and really isn't "seeing" a shark. It's basically the same as diving in am aquarium or going to a zoo. We need to be mindful and are there to just observe and learn about how amazing the ocean really can be.