Fanboys, calm down. Realize that some games have difficult entry points.
1) Don't expect a Survival Horror game to be Survival Horror - Here's something to know about the survival horror genre, something to realize, since it's existed no two series have been that much a like. Survival Horror is this fairly loose term compared to third person shooter, first person shooter, hell even most video game rpgs (including traditional Wrpgs and traditional Jrpgs) have more in common than some Survival Horror titles do. And on the outside of things, to general population, to even general gaming population, to someone who wasn't around for the survival horror boom that was before RE4, you reasonably may not know any of this. Silent Hill, Resident Evil, Dino Crisis, Dino Crisis 2, Parasite Eve, Alone in the Dark, Eternal Punishment, some of these games have hardly anything in common. There's not many games under the Survival Horror title, yet there's never been a lack of variety. So yes, survival horror can be a tricky landscape, someone makes in error jumping in, it should be expected (from the fans).
2) It has the number 4 on it. It videogames, it seems like there's enough times that this doesn't even matter at all to understand that this doesn't always matter. Silent Hill 2 is a self contained story, Resident Evil 4 (excluding that the game doesn't give a single shit if you know Ada or Wesker) is also a self contained story (so Shamus has only a small point there), the main series of the Final Fantasy games are self contained stories, Disgaea, Persona, Bioshock Infinite, the Elder Scrolls, sometimes these are just titles to tell you what a games is going to be like, united under a banner where some assets get re-used.
3) It has the number 4 on it. Again. A good story, no matter videogame, movie, book, has a job to bring you into the world, Now, not every detail all the time can be explained, but efforts should be put forward. I'm not sure I've read a book series that doesn't spend a sentence or two re-introducing characters for those who may not have read the previous entry(s) - because that happens, people pick something up, even if it has a number on it, and dig in, and they should be able to without being utterly lost - most so in videogames where other mechanics change change over time, and at times trying to start at the beginning means a rough interface, different controls, and needing an outdated system. It is unreasonable to demand anyone play anything from the beginning of a long running series. Now, that being said, as before, Resident Evil 4 stands as it's own thing from the rest of the series, and therefore has less of a problem with some of these points. However, the game does not care if you know who Ada and Wesker are, and where Wesker could easily have been left out of the game entirely, Ada appears enough to warrant more of an explanation, especially since in later releases of the game she gets her own game mode. Further more, they give you an idea of what happened to Krauser, but almost act as if playing a previous game in the series may reveal further information on him, which is not the case, Krauser is a bad written character, he's hardly introduced, we are told very little about him, until the game feels like it later on, and even then we know very little.
4) It's your fault for not getting the controls. NO. Just no. Any one of you, who hasn't been a long time, old school, Resident Evil fan have no idea. The Resident Evil 4 controls have been mass produced, they are in so many games, sometimes reworked, retooled, but the core is there. How the game controls, from the camera, to the quick time events, have become standard, and have never been a wide spread barrier entry. You are being silly. Some people do not like games that play a certain way, it happens. Any long time RE fan should be able to understand this, as the old series had two heavy complaints, the dialog and voice acting sucked (yup), and the controls were horse shit, and as a Resident Evil fan you either found the controls to not be a problem or put up with them anyway, but at the end of the day had to understand why some people couldn't deal with it, because it was most of what you'd hear about the games, it was/has a decent chance of being the number one reason people could not get into Resident Evil (pre 4). Some games are not for some people. It happens.