"Walk a mile in someone else's shoes"

I suggest you try being a landlord before proclaiming judgement, even as a thought experiment. Find a property you might purchase (with a mortgage) to rent out. Calculate the cost/liability. Look up the renting laws in your area. Look up the market price for renting. Look up maintenance costs and schedules. Estimate time spent interviewing, handling paperwork and accounting, scheduling maintenance. Calculate net profit.