Not everybody has unlimited IP from years of play. Its an unfair cost to those people who do not have the IP for it.
Having unlimited IP from years of play is just a natural outcome of system where a resource is accumulated over time but being able to spent it has limits. Over time you end up only gaining more and more with nothing to spent it on. This is not a problem, just a natural outcome, you already have everything you can buy or want to buy so just play the game and don't worry about IP.
Basic game settings and options should never be tied into resource management and spending, these are two different sides of the game that should not cross over. It's like asking to use your IP to change your music volume, its idiotic.