Not being 100% effective isn't backfiring. No law is ever absolutely effective. But making something illegal objectively makes it more difficult to obtain, and is certainly effective at reducing access, even if it's not 100%.
I hope with this added context that my previous comment will make much more sense and you can interpret it closer to what I intended.
I'll just add, I don't think most people work in those absolutes. So I'd be wary of jumping to the extreme interpretation. People might interpret you as being disingenuous and using the logical fallacy "logical extreme" or "reductio ad absurdum". But I'm pretty sure you're not doing that because then I'd be grossly misinterpreting you, right?