Damn that's hilarious Herzog! Reminds me of the jiu jitsu cartoon they have floating around.
I've read every post here, and I can't believe I missed this thread entirely but I'd still love to give my two cents.
i feel we should learn leg locks simultaneously. If one doesn't want to learn the submission, s/he should at least learn the escape. I think it's good etiquette to ask, before you roll with someone, which leg submissions they will be doing and which they are comfortable with being put on them. Then, right off the bat, you'll know their experience level, or level they are willing to delve into.
So that you don't practice bad habits, you should set aside rounds that are dedicated to anything but leg locks. That way you can focus on your passing game, and other sub game. Sure, let your opponent put them on you so you don't get rusty on your defense, but really focus on rolling with and without leg locks. You'll begin to see your habits, both good and bad. I've noticed that when I'm trying to pass guard(leg locks allowed), and I miss, I'll just go for a toe hold and end it quickly. It's no fun knowing you can beat a guy that doesn't know them that well. So I'll focus on purely passing, etc...
I'll tell you what though, ADCC trials, I got slapped in the face because I didn't know leg lock defense as well as I should have. Never again, I told myself. Now if I tap to a leg lock, I know that I had a grapplers chance to get out of it.
My leg lock game has allowed me to hang with the Mendes brothers, Jason Manley, Gokor, Manny Gamburyan, Sevak, Roman, and Karen. These are world class leg lockers, and sure I'll tap to their subs, but when I go against nicer guys, it's night and day. So leg locks have improved my overall game, and now I can focus and whatever I want to focus on, be it passing, inverted, etc., because I know I have room to mess up. And, while I'm still learning all the other techs, I want to see when and where leg locks can be dropped on me.
[One final note, sorry for the lengthy post]: Even if you get the leg lock in, don't yank their leg off... practice "Touch and Go". Even if I have the lock secured, and my opponent hastily grabs my leg, I'll try to escape their leg lock knowing that I could have taken their foot home, and I'll even tap... Why? Because I value my foot more than the satisfaction of breaking someone's leg...