If the rule has been done for saving money, laugh about it and ditch it. There is no rule that help teams to spend less money. After all they are given money from various sides to be competetive.
Indeed. The teams are always going to spend whatever money they can to gain an advantage. Restricting which areas they spend that money on is arbitrary and pointless, and it could be argued has detracted from the racing with so much of their budget going into aero now (which makes it harder to follow cars through corners).