hen had 'trouble' with their pesky tenants (who actually are responsible for paying off your mortgage while you do pretty much fuck all )
give it a rest, will you.
The tenants are very happy to benefit from the transaction, have a set rent to pay every month, call if any problem arises to get them fixed , have complete flexibility and being completely untouched by market crash.
Landlords provide a service, take financial responsibility for all unexpected repairs, will be the one losing out in financial crash, has to fix the property after tenants leave. The landlords take a risk, the tenants don't.
No one is asking you to feel sorry for one or the other, but let's not pretend that tenants are poor victims of evil landlords, it's a business transaction and sometimes one party benefits more than the other.
It's because of bad attitude that landlords are strongly advise to change tenants regularly, to keep the property in good repair and the rent at the market rate, but mainly to avoid any issue!