In hard real-time software, you have a performance budget otherwise the missile fails.

It might be more maintainable to have leaks instead of elaborate destruction routines, because then you only have to consider the costs of allocations.

Java has a null garbage collector (Sigma GC) for the same reason. If your financial application really needs good performance at any cost and you don't want to rewrite it, you can throw money at the problem to make it go away.