You're buying X gun in the game that you'll get at some point anyways, and generally if you're the type to spend money on the gun, you're already playing it on a low difficulty setting so it's not as if you're seeking the challenge.
Unless the design the game specifically to be nigh impossible without purchasing weapons, it shouldn't impact normal gameplay for the majority of people so they can completely ignore the feature.
As for your cheat code reference, I wouldn't say that's a proper analogy, but to go down that road a bit Gameshark and Game Genie say hi : )
The opening scene in the first one is great as a horror tool. Unknown enemy chasing you down a corridor, you have no weapons and can't get a good look at him, so you have no clue wtf it really is.
Beyond that, a big part of the first one was the feeling of being alone in that lifeless ship filled with tight corridors and ominous dark rooms. The first 2-3 vent based jump scares worked, but jump scares only work when they're not predictable. It was more the atmosphere that was intended to be scary rather than the cheap jump scares.