I can tell you that every few years, we are hit with a large "maintaince" bill--a new roof, a new plastering job for the pool, new landscaping, etc etc.
I can't imagine that it is any different in a condo or townhome. Property has to be repaired and updated. It's a fact of life--and sometimes, these things cost big bucks.
If we put away say $200/month toward some upcoming repair, chances are it wouldn't be enough to cover the cost of a major repair when the time came.
In that way each member of the association pays for the depreciation "consumed" while a member of the association. When selling, buyer should compensate seller pro-rata for the value of the accumulated fund since the seller contributed to the depreciation fund while a member of the association.
Buyers should not then be surprised by large special assessments; but they WILL pay larger annual association dues.
Responsible non-profit institutions such as private schools and churches do this. Why shouldn't homneowner associations?