Business plans are mostly about organizing, formalizing, and committing to a specific plan_of_actions. Such a document generally presents the objectives, strategies, analysis, and a detailed roadmap for implementation. Underlying a plan_of_action is comprehensive analysis of historic, current and proposed results all supported with assumptions. If anyone doubts the interest in business plans, a Google search returns more than 62 million and Amazon list more than 77꺜 titles concerning this subject.
That is a great thing to make sure you have in your business plan, that your business will be built around those real customer wants. Do not make callous assumptions, or statements like "I know what people want", "People are going to love this", and so on. Have you done your research? Do you really know that the people you will be targeting want your product / service, and crucially do they want it AT THE PRICE that you will be offering it at? Whilst confidence in your plan is fantastic, you must make sure that it does not lead you down a blind alley along a path that is not desired by your target market. Don't assume what customers want, do your research and make sure that is clear from the start in your business plan.