The correct way to lock a bike is with the lock around the rear wheel.
No Alan, that's the correct way for you to lock a bike.
Cut a rear wheel in 30 seconds? Good luck with that. Gotta get through the rim, the inner tube, and the tire. And then, the crook can't ride off on the bike.
Couple of quick snips with the nice big chain cutters that got stolen from Brixton Police Station last year should do the trick. The three in grab on those are more than enough to get purchase and no sawing required. Who said bike theives actually ride of on every single bike they steal. Police in London have on more than one occasion arrested a gang of bike theives going out to steal en masse with a transit van. They don't care about loosing one or two components of a bike, they'll just do a rebuild with something from another bike. If there is one thing to be said about the infamous Brick Lane bike market (virtually all stolen) is that they know a lot about bikes and are almost professional in making them saleable. Your tactic is no guarantee in these parts, nothing is.
There is no rational reason for anyone to still be using "pretend" locks that can be broken by half-witted dopers in thirty seconds.
Do you concede that a cable with a sold secure rating is a proper lock?