Residential properties usually have short term leases. You have minimal incentive as a tenant to plant flowers, buy shrubs, etc. You have minimal inventive as a landlord to make the house look any more attractive than it needs to be.
Landlords don't maintain property to the same standard as an individual homeowner, when they do, they use more efficient service models (ie. a single crew with a single set of tools) to do so.
Tenants participate less and have much lower engagement. They have 1 year leases, and have less at stake. In my community, renters participate 60% less in terms of voting. There are 150 members of my local neighborhood association, and per a recent survey, 90% of participants are homeowners. They mostly solicit membership by dropping flyers and advertising in church bulletins. Per census figures, the population of renters is somewhere between 60-70% vs. homeowners.
The last point is that without homeownership, incentives shift to multi-family dwellings because they are cheaper and more efficient. Single family homes for rent are usually an aberration in my experience. As a homeowner in a city that is mostly rentals the per-unit taxable value of a multi-family house is significantly less than a single family.