The reason for all of the complaints is because leading up to the games release the developers consistantly said this would be a PC game that was brought to the consoles and not the other way around. Look at the quotes about Battlefield 3 that are in the gaming news everywhere right now and you get an idea of what I'm talking about. The sad truth is this game WAS made with consoles in mind first, rather than being scaled down to work with them. There is a big difference.
I'm sure eventually with a DX11 patch, texture pack updates, SDKs and the mods that come with them, multiplayer with more than 16 players, etc etc...yes this will be a great PC game. However, because this was a console game first all that stuff was put on the back burner and will be released "when ready", if ever. The reason I personally am so upset is because I preordered the game based on lies. I haven't played in weeks and won't until the game is finished. I would have waited and bought it for $40 or whatever its going to be at that time rather than paying $60 for a game I don't even want to play. I don't hold any ill will towards Crytek, I just think they misled a lot of people and there are a lot of legitimate reasons for people to be angry. I think a lot of people are complaining just to complain, but there are also a lot of people that are excusing everything just to excuse everything. Neither side is 100% right.
TLDR; EVENTUALLY this will be a great PC game, right now this is a great console port.