I am not sure if that is true.

My girlfriend had very minimal activity on her credit, and she recently applied for a loan, and was approved for a very signficant amount. When she inquired about it, the lender said that minimal activity is often a sign of someone who is not desperate for credit. Meaning that they are more willing to give a higher loan to someone who doesn't look like they need the money. But that might have been exclusive to this experience.