It’s not alright when 4 people bought homes in a development never suspecting their right to smoke in there own unattached single family home would be taken away! Give me a break!
It sounds like they don’t smoke, so it really only affects who they can sell to. And where does it say they live in unattached single-family homes?
Besides, when they bought property in a HOA, they knew or should have known that the HOA could pass new rules.