Do games like L4D & L4D2 prove that gamer's aren't patient?

Note: There was probably a post similar to this I didn't read or remember, and if I "copied" it, I apologize.

I must confess: I love killing zombies. The sheer satisfaction of red hot bullets tearing through the zombies' flesh and empty cranium. I loved all the Resident Evil series (except for the travesty that was RE5, and yes, I enjoyed RE: Outbreak 1 and File#2). I've watched a countless number of zombie flicks from oldies, to remakes; but ultimately, I was waiting for the ultimate zombie game.

Enter L4D. When Valve announced it back in 2006, I was more than excited. I was ecstatic. Valve was a respectable developer, catering for PC gamers. It promised to emulate the feeling of being in a zombie apocalypse. I knew this game was going to rock. A few frustrating (and I mean VERY frustrating) delays later, I had my copy. I was trembling with excitement. I fired the game up, and the opening cut scene blew me away. I told myself "This game is going to be AWESOME!!!"

A few lag issues and another few annoying players were in the way, but I was having fun. but something kept irking me. I didn't have that overwhelming feeling I though I would have when I dreamed of this game's release. Instead, I kept thinking things like "What if they added..." or "What if they did this instead of..." In short, I personally felt there was a lack of content. To show you what I had expected or wanted, I provided a list:

*Sprint option
*Aiming down the sights
*Melee weapons (L4D2 provided this, however); and more dynamic melee weapon differences (i.e. attack speed, damage, swing radius, reach)
*"Crawl" option when a player is down. (Additionally, another player can "drag" the downed player; the downed player can use his/her weapon, while the other can only use a pistol while he is dragging the player.)
*Scavenging items
*NPC interaction.
*Bloodier survivor deaths
*More spontaneous gameplay, instead of going from Safe Room A to Safe room B
*More engaging story

But while I was conjuring these thoughts, I was thinking, "They must have left these out on purpose!"

Now (Sorry for taking too long) is the question I want an opinion on: Are gamers not patient? Adding more features meant a deeper learning curve. A lot of individuals hate steep learning curves, so something simple is what caters to them. I realized L4D is more of a pick up and play, rather than being immersed inside it.

L4D, for me, was a like a unfinished hamburger; the core ingredients were there (the hamburger and hamburger buns) but the other, important ingredients that compliment it and make it even better were missing (the cheese, tomato, lettuce, pickles, etc). It was good, but it was missing VARIETY. It costs more to make a more extravagant hamburger and people might even not like the additional ingredients, so the makers (or developers) stick to what is simple and what works: Sausage and buns.

I am not bashing L4D or L4D2. I still have a lot of fun with it. I was not one of the boy cotters, nor was I planning to be one. L4D, simply, did not meet my high expectations.

So, I want to ask the readers (if you read this) of your opinion. Should developers make a more game diverse, or do you believe in the "if it's not broken, don't fix it" idea? Should gamers be more patient?

And finally: Was there a game you were so excited about but ended being a disappointment? What features would you have added/removed to this game? If there was a sequel to this particular game, did you find it better, or worse, than it's predecessor?