Wife doesn't want to increase rents

[Zachary Jensen]

I'm just about to close on my first rental property (house-hacking a duplex in a small town outside of San Diego, CA).  The previous Landlord raised rents 3-5% every year on this property, so it is currently rented for market rent to some great tenants who have taken good care of the place.  My wife is a wonderful person and very generous.  As a result, she doesn't want to continue increasing the rents on a yearly basis.  I could really use some help making the case for the importance of yearly rent increases.  I understand that property taxes increase on a yearly basis and that any maintenance costs also go up on a yearly basis.  What are some of the other reasons for maintaining regular annual rent increases?