Detent.
The detent on an axis lock knife is non-existent. These are overwhelmingly the easiest knives to have their detent overcome, in my experience. I won't carry an axis lock knife doing certain activities, even if the spine of the blade is against the seam of a pocket. Sometimes I don't have pockets. The axis lock is the last lock I would ever want in such a situation. Spyderco Pacific salt is what I trust there.
You're right that it's a weak detent. I carry a Rukus with a heavy, 4+ inch blade, and I can shake it open easily without touching the lock. I can also easily shake open the CS AD 10 with the Tri-Ad lock.
When I get the blade tension set correctly, I can hold the Rukus in a horizontal position, pull back the Axis lock, and the blade will fall open and swing freely a couple times like a pendulum. And the blade lockup is solid. To close, I pull back the Axis lock, and let gravity do the closing.
I don't look at this detent/opening characteristic as a bug. I see it as a feature.
I've never had my Rukus open accidentally, even a little bit, and I've been carrying it for more than a decade. Gardening, wood chopping, running, cliff climbing, hiking, roll-on-the-ground dog wrestling -- never an issue.
I've never broken a spring. The lock has never gummed up, even though my pockets are often full of straw fragments from no-till gardening. I love the weak detent.