It fundamentally boils down to fairness and responsible corporate planning. Some owners in this scenario pay much more than their fair share, and some owners pay much less than their fair share.
Somebody always gets holding the bag.
In most cases, special assessments as an ongoing way of conducting business at an association should not even be an option. Special assessments are designed as the solution for emergencies, not regular common area expenses. Certainly, many homeowners can individually manage their money to gain a greater return than the association, which has limited investment options. But the association needs to be run responsibly, and demonstrate to its owners that funds will be available when they are needed. There is no guarantee that the Board can pass a special assessment and collect the funds in sufficient time to meet a pressing Reserve expense.