Partly fair, but exaggerated: the statement that local events are a always-present and major component in planning is too categorical. In Senegal, a business traveler coming for a meeting in Dakar will not care about the dates of the Grand Magal of Touba, even if it is a major national event that disrupts transportation and accommodation.
Their priority is efficiency and proximity to their workplace.
The impact of local events is therefore conditional and not universally decisive, depending on the specific objectives of the trip.