Just speculation, but at least in the US it is/was marketed as "legal weed". Nearly everyone that I knew trying it did so because their weed connect dried up.
Is the weed situation much more lax in the UK than in the US?
Is the weed situation much more lax in the UK than in the US?
If you get caught, more often than not it is confiscated / thrown away.
Same for growing for personal (no scales, no baggies, no tick list at the property, no "sorting a few mates out" - actually personal), a few plants and nothing will happen, at worst a few hours of community service
And a criminal record, and never being able to travel to the USA or various other countries again for the rest of your life.
Nothing big...
You have a funny idea of decriminalisation.