Its more of the levels and degrees of action taken rather than the action taken itself.

a person owning 1-3 properties, properly maintain the properties, not gouging the heck out of their tenants and looking for long term tenets who will be allowed to live in the property (hang pictures and make it to a degree their own) is in the realm of what i would consider a ethical.

As opposed to slumlords who buy properties to exploit for maximum profit, barely maintain it and cycle through tenants who occupy and pay for it for 1-2 years before moving because of constant rate increases.

Its the ethical and humane management vs exploitive management.