I don't know how "sensible" the change is, other than you're not going to automatically be treated like a criminal. It is a step in the right direction only due to the latter. If we treated other things (alcohol, for instance) the way that Uruguay is treating cannabis, I think there would be outrage. A national registry of drinkers? Limits on the amounts that one can purchase? That's some heavy-handed bureaucracy at work, and shows that just because something is legal, doesn't mean that it is free-as-in-freedom.
I think you're right about the outrage that would follow a registry of drinkers. However, the degree of outrage something causes is not decided only by how sensible or not it is.
We tend to compare new developments with the status quo. "Sensible" is not used here as an absolute, but to congratulate a step in the right direction.
Production isn't regulated, only its sale, in small amounts. It's better than nothing, but it's still screwed up. If you want to run a coffee shop, you can safely sell weed without fear of getting in trouble (as long as you don't sell to minors and don't sell large amounts). However, you still need to buy what you sell. Growing it is illegal (and prosecuted), buying it is illegal (and prosecuted). Worse, if you decide not to grow it yourself (and that surely is the safest option), the only place you can buy it from is organised criminals.
The sad part here is that the majority of current big parties appear to lean towards criminalizing drugs entirely again, rather than follow Uruguay's lead and regulate or nationalize marihuana production.
That's a dated, but sticky image of us you have there. Fortunately, our leaders are doing their utmost best to rid ourselves of it, so it shouldn't take long.