Do you want a high credit rating, or do you want money in your pocket?
If you don't need to borrow money, then you don't need a credit rating. In this day and age, a house is no longer a given (since they have proven to be extremely poor investments at times), so you don't necessarily "need" a mortgage anymore. If that's your situation, then your credit rating means a lot of nothing. You don't need a good rate on your mortgage. You need cash in your pocket.
If you don't need to borrow money, then you don't need a credit rating. In this day and age, a house is no longer a given (since they have proven to be extremely poor investments at times), so you don't necessarily "need" a mortgage anymore. If that's your situation, then your credit rating means a lot of nothing. You don't need a good rate on your mortgage. You need cash in your pocket.