Actually, the "default position" of the ILS assembly is unlocked, and yes, because the torque lock spring in the locking arm holds it down in that position. You have to turn the "key" to lift the locking arm, against spring tension, so its post can then engage in the corresponding spot of the hammer groove and "lock" the hammer from moving.
Now, if the spring's bottom leg isn't properly located within the recessed slot in the upper part of the bolt channel, then the spring can't keep the locking arm from lifting, and remaining up, long enough to potentially create a problem if it finds the part of the groove that will stop the hammer's movement.
Kind of like if you don't properly locate the slide stop lever spring when reassembling a Glock. If the spring isn't able to exert the intended tension, it can't prevent the slide stop lever body from being lifted during recoil, and it's possible for the upward "bounce" of the slide stop lever to eventually "time" itself hitting and engaging within the slide's slide stop notch, locking the slide back. The lever spring works by the spring holding it down, so when "parts flutter" occurs (meaning the expected minor parts movement, including bounce, occurring during recoil), the slide stop lever doesn't bounce high enough to engage the slide. People who ought not to detail strip their Glock often unknowingly create such a problem for themselves (not positioning slide stop lever spring).
I could certainly see how someone might open up their S&W revolver and set themselves up for a ILS "problem" by removing the hammer (and maybe the bolt), and unwittingly (and unknowingly) dislodge the torque lock spring's bottom leg.
Or they damage the locking arm's spring.
Or, it's not impossible to every once in a while end up with a spring that's defective by reason of being out-of-spec, or has a materials problem, or maybe just wears out after long enough heavy use. (Kind of like how that hand torsion spring finally had the tail break off and cause the cylinder to stop rotating in that M36 the owner brought to me yesterday.)
S&W has been selling their assorted J's made with the ILS to LE agencies, as well as much greater numbers of them to individual cops & private citizens. (Sure, you can always find some small agency instructor/FTU trainer who may not approve them, but then there's more than 17,000 LE agencies in the US.
) Every time I've asked one of a few LE reps, and the folks in the actual LE sales dept, about whether they're removing locks from J's being sent to LE contracts or individual officer sales, they seem puzzled by the question, and answer NO. I keep being told that the guns which are normally made with locks are being sold to LE with the locks. Of course, they make some of the Centennial (internal hammer) models without locks, for those folks who want them, and will just as gladly sell them to agencies (or the public).
Buy what you want. It's your money.
Don't worry about hurting the company's revolver sales. They can't make enough of them to satisfy the huge demand. If you don't want one with the lock, pick one of the few models made in runs without the lock. Buy a used gun. Keep the market for used guns strong, and the prices high.
(Don't hold your breath for the lock disappearing from the exposed hammer revolvers, as their legal staff is apparently a strong force for keeping the lock on those models.)
They're the ones that have been requiring attention, correction and repair. (To be fair, cops can be harder on guns in many ways than many firearms enthusiasts, and the mingling of neglect & abuse can eventually result in problems now and again. 
