Sometimes companies purposely design a game where some obscure parts are obscure in hopes that they buy a licensed strategy guide.

It's sort of the same reason why most old school games were so tough. While sometimes games were hard because they were an arcade port or developers only knew how to make arcade tough games, developers also didn't one some snot nosed kid to rent the game for a couple of days, beat it, and decide not to buy it for that reason.

Well, at least that's what I think.