I'm not missing the point.
Freedom for Property owners not Freedom per Citizen.
Why is land ownership a requirement to grow a plant?
Why is it a requirement?
Because a landlord has a right to say what can or cannot be done on their property.
Some apartment complexes have rules against pets... (which are legal)...
Some apartment complexes have rules against youth (you have to be 65 to live there) but being young is not against the law.
Some landlords require that you do not smoke in their building. Smoking itself is still legal.
This law simply does not FORCE landlords to condone people growing cannabis in their spare bedroom. It ALLOWS landlords the CHOICE. And choice is still legal.
If your landlord won't let you grow, find a new landlord. Or save your pennies and buy a house. Or find another solution.
Hope that helps.