The reason RE4 and Street Fighter 2 even CAN be monetized when re-released a dozen times is because the gameplay is THAT good.
People rarely bring up how hilarious the plot/writing is in the game as a negative because you can shoot a zombie in the knee, run up and spin kick him into his friends, knocking them back, then throwing a fire grenade to watch them all burn to death all by yourself like a bad ass and eat a large bass you kept in a briefcase to regain your health. Nobody else is there to take your ammo/herbs/miscellaneous fish, there's a random guy (guys?) who upgrades your weapons, sells you new weapons, sounds like a pirate, etc.
There's escort missions, but are you just escorting a helpless girl from one place to another? No! You tell that bitch to hide in a trashcan while you're out shotgunning chainsaw-wielding freaks, shooting tentacle monsters sprouting from a guy's neck, suplexing zombies wearing church cloaks, and shit-talking zombie midgets.
Motherfucker, if you don't want to play that game again, then something is wrong with YOU.