There are problems with designing a striker fired pistol that you
don't need to pull the trigger to disassemble. It would be difficult. By definition, the striker is held back by something (sear), and that sear is usually located in the frame. To get the sear out of the way of the striker, you have to pull the trigger.
To design a striker fired gun that doesn't need the trigger pulled, I think you'd have to do one of two things.
The first would be to have the slide come off the back of the gun instead of the front, which would create an obvious problem if the little part that held the slide on became broken. I've never had a slide hit me in the face, and I don't particularly care to. This would also create an issue with the location of the recoil spring assembly, but you could probably figure out a way to get it done.
The other way to do it would be to have something like a two-piece sear, where half is located in the frame and half is in the slide. When the trigger was pulled, the half in the frame would push the half in the slide up, and release the striker from the top instead of the bottom. When you disassembled the pistol, the striker would stay cocked, and each half of the sear would stay in each half of the gun. This would require a fairly large sear assembly, and the added parts would come with an increased risk of malfunction, and probably add a significant degree of complexity to the slide. Then again, I'm not a gun designer, so I could easily be wrong.
Instead, I think I'll just stick to my 1911's, which don't require the trigger to be pulled to disassemble. Incidentally, a 1911 can be disassmbled with a live round in the chamber, although I definitely don't recommend it.
Also, the "discharge" in question in this thread is definitely a Negligent Discharge. I can't think of too many ways to "accidentally" pull the trigger of a loaded gun, although I'm sure it's possible. However, he pulled the trigger on purpose, which he fully intended to do, so by definition it's not an "accident." In any case, I hope he's OK, and that everyone can learn something from his misfortune.