Not commonsensical and to my mind a menace to society at times. The reason I get so worked up about this issue is that the legislation could have been better written at the time. To my way of thinking a lock on a folding blade is a safety feature for the user just as a folding blade in itelf is safer to carry in your pocket than a fixed blade in a sheath. Of course from a legal standpoint I can perfectly legally carry my locking SAK when I have a particular use for it, but it would be nice if that privelege could be extended to EDC and did not have to worry about running the risk of having to defend myself against over zealous cops. Oh well I should let it rest, no point being a keyboard warrior every time the subject is raised.
Having griped at the word of the law myself for quite a while years ago, I do accept it is written with a degree of ambiguity, and very well written too.
It allows carry of locking folding knives (a Stanley knife for example), and fixed blades (electricians knife). It allows you to go and do whatever you want to do with your knife.
and did not have to worry about running the risk of having to defend myself against over zealous cops.
.... Assumption? Or experience?
For your record, a folding knife is not necessarily safer to carry in your pocket than a fixed, sheathed blade. Once with a Tenacious (work knife, tree surveys), after jumping a ditch I put my hand in my pocket and slit my thumb. Second time, different knife, delved in my rucksack (dumped pack hard on the ground) and got a good stab.
The knife law works fine. Ok, sometimes I find myself in a shop picking up a few things and realise I still have my work folder in my pocket. So what, I'll take it home. And if I feel I may want to open an envelope, or help with decorations at the local pub, put something taskworthy but discreet in my pocket.