Your posts make it very clear what you think of landlords. Perhaps they should ALL sell, then when you can't find a home to rent you'll really have something to bitch and moan about.
I'm not against private tenancies. They are an important part of the UK housing market and they do offer important flexibility for those who need it.
But: private tenancies should be the exclusive domain of properly regulated companies and housing associations. These would be much less likely to end tenancies for personal reasons - as in the case highlighted by the OP. While companies do go bust sometimes, generally 'illness in the family' doesn't lead to the short-notice expulsion of tenants from their homes.
If all landlords sold their homes tomorrow, property prices would fall to a level which would see more people able to buy their own properties.
In reality many houses would be sold to companies, housing associations, and local authorities. Properly regulated (safeguards would be needed against vulture companies - I'd rather see all property go to HAs and LAs), these bodies would be far better landlords than the amateur landlords we hear from on threads like these.
Best of all they could offer private tenants proper security of tenancy, as the systems in many European countries do. Most renters in this country are on between 2 and 12 months' notice to leave their houses at the discretion of their landlords.