If I'm in a streetfight, I'm not going to be too worried if we knock shins because I've never heard of a street fight where both opponets are kicking. And if you mean someone using an object to strike at my legs, they'd be going for the knees. But if they did hit the tibula, no amount of conditioning would help and you'd have a broken leg.
And as far as "could happen and will happen" being a big difference, you're right. They are. But the more you do things that involve risks that "could happen" the more likely they "will happen". And anyways, the author of that article cannot say it "will happen" because there may be just one person that it did not happen to and he'd be writing false truths.
Also, "No pain, no gain." You're the one who's deadening the nerves in your legs so you feel no pain. I'm quite alright with occasionally hurting my shins and walking it off. No pain, no gain. What is conditioning for? ELIMINATING PAIN. And according to you, that's the only way to gain.