It sounds great but you do get registered in a government database. You never know what that data is used for in a later stage (think about health insurance claims rejected for example).
The dutch government also did implement a registration a while back, that was the day I quit buying weed in a coffeeshop.
It's bullshit... people who drink alcohol aren't registrated as well.
Why not let anyone grow it if they want, without the registration.
The idea to use the tax income to help people addicted to hard drugs is great though I think.