The better ones certainly are. I have one.

When the lock is open, you can rotate an inner cylinder (not accessible while the lock is clasped) to a position which allows the outer rings of the dials to be moved to change the code.

Bought at a Canadian Tire store in Richmond, British Columbia. (See, even available in Canada.)

Oh, my mistake! Mine doesn't have that ability, and if you make that assumption, the article is accurate. I didn't know some could do that.

So, the best way to use a lock like that would be to pick a non word sequence. And regardless of the combinations these locks and all their derivatives are very easily opened even if you don't know the combination.

I once destructively opened a friend's U-Lock in about 60 seconds. (The key broke, didn't have copy.)

I took a 10 dollar hack saw and sawed through the main bar of the lock (not the U).

It was like a hot knife through butter.