Should Landlord be Allowed to Discriminate Against Existing Tenants?

Is there a good reason for the practice of charging higher rents to existing tenants? I personally am paying about $3,000 more for the next year than a new tenant who signed around the same time.

It seems very inefficient to incentivize moving like this. Churning tenants is directly keeping 9% of vacant homes from being occupied at any given time, and costs both sides money. So as long as banning the practice doesn't move rents a ton both sides win.

Half of all moves are for lower rents so addressing this could significantly impact churn rates. Cutting churn by a third and adding an equivalent number of units for sale would add 13% more units for sale but the biggest moves would be in time on the market and the ratio of perspective tenants to available units. So the amount of vacant units needed to keep markets renter friendly could drop significantly and landlord lose out on false hope of filling quickly.

Allowing discrimination against existing tenants also provides landlord committing illegal discrimination or retaliation a legitimate excuse for charging a higher rent to undesirable tenants.