The idea that local events 'directly unify' trip planning is a simplification that ignores each person's priority reality.
For a student like me, a festival in Sousse won't 'unify' my decision; it will just make accommodation more expensive and the city louder, which is the exact opposite of what I seek for studying.
There is a clear asymmetry between what the average tourist seeks and what the budget traveler or those with specific goals like studies, family, or relaxation look for.
Anticipating these events is mainly about knowing whether to avoid them to find some calm and affordable prices, not to adhere to them for a pseudo-"unification".