Pulju - A bit of a weird case, as kids his age usually don't play in the AHL at all. The fact that he's already had 49 AHL games before his 20th birthday is far from the norm. He very well could see more AHL time next year, though I expect most around here (and the player himself I'm sure) would view that as nothing but a down arrow...which isn't really fair but perception isn't always objective.
Caggiula - College guys who spend 4 full years playing against adults in the NCAA generally have fairly mature games, so it's not surprising when they start in the NHL right away. His first year wasn't all that bad, his problem was his sophomore campaign where it seems like he just replayed his rookie year again, not much progression in his game.
Benning - Same as Caggiula.
Nurse - This is a valid example, I agree that a half year or more in the AHL wouldn't have hurt. But in his case, I could be wrong but wasn't he initially called up due to injuries with the big club? Regardless, while he did have a rough rookie year on a really bad team and an injury riddled 2nd season, he became a legit NHL dman as a 22 year old so I don't think his development wasn't hurt that much...him turning into a top 4 dman at 22 yrs old was probably as good an outcome as we could realistically expect even if he had spent a full year in the AHL.
Slepyshev - He did get around 60 games down in Bakersfield and in his final 10 games he was starting to dominate the AHL so you could argue that he was ready to move on to stronger competition...and it's not like he came to North America as a teenager, he'd spent a full year playing against men in the KHL and was reasonably productive.
I think going forward though, we're going to see a development curve more like what you're wanting to see for promising talent like Yamamoto, Benson, Maksimov, Safin, Marody, Bear, Jones, Samorukov etc. I would expect they're all going to see at least some amount of AHL seasoning before being seriously considered for NHL employment.