Haiku hotels are not really a thing. There are many bed and breakfasts, vacation rentals and rental homes in Haiku but there is virtually nothing when it comes to actual resorts. There are two main reasons for the lack of Haiku hotels. The climate and the zoning.
The climate of Haiku is beautiful! If you like rainforest climates. The area is vibrant with all kinds of green foliage from the constant rain. From time to time the weather will clear up and you will be able to enjoy the outdoors but there is a large amount of the time that the weather is rainy in Haiku (which is almost every afternoon).
The zoning is the other issue that makes it so there are not any hotels in Haiku. The island of Maui has a similar development plan to all of the other islands in the state of Hawaii. Most of the resorts are to be built on the South and West side of the islands and the North and East sides will be left to be developed by the locals. The tourists really seem to come to Hawaii for the sunny weather so most of the short-term rental demand is centered on the other side of the island anyway, so the plan has really only put the natural building trends to paper.