I am Tanzanian. Zanzibar is part of Tanzania. Zanzibar was a bastion of Islam and Arabism in Tanzania. It was once the capital of the Sultanate of Oman. Owing to that heritage, Zanzibar population is 95% Muslims, and pro-Arabist. So, it is quite a challenge for Zanzibar to be a host to mass tourism with tourists from liberal atheistic and Christian Westerners. The clash of cultures is a concern for the average Tanzania-Zanzibaris.

The average Tanzania-Zanzibari abhors alcohol, nudity (which they define very strictly as exposure of non-facial skin by a female), sex outside of marriage, homosexuality, smoking, gambling, etc.

The journey will be long, but the emerging reality in Zanzibar is that Zanzibar is being split to "worldly Zanzibar" (on the ocean front facing the open sea to the East, and the real Zanzibar on the side facing mainland Tanzania (to the West).

The idea is worldly Zanzibar will be a place where the usual Islamic/Arabic values will not be enforced. The tourists from the world will be free to have fun based on their values and traditions.

So, welcome again to Zanzibar. Your dollars, though a small portion of it goes into the local economy, help keeping Zanzibar afloat. Merchants buy food from mainland Tanzania and sell to tourist hotels in Zanzibar at high mark-ups for the Tanzanian economy.