The fuss is because some of us expected the game to work better in this area than it will-- however unrealistic it apparently might have been, people looked forward to that and talked about it, and 343i did nothing to mitigate those expectations. After releasing this compilation people didn't expect, including every single map ever made, and blowing all previous versions of Forge out of the water, I think a lot of people got their hopes up more. That is, until today, less than a week before release, when a lot of people have bought consoles and pre-ordered the game. I haven't, but I feel for people who did do that and did it mainly for custom games and weren't clued into whatever cost-benefit analysis or server architecture thing or whatever it is that apparently makes dedicated servers for custom games unrealistic.
Now I'm wondering if this how the people feel who are mad about how small Destiny is... probably not, they seem a lot madder or more bitter, I'm mostly just disappointed. I think the volume of posts, and the fact people are explaining and defending their thought process, and other people are telling them why they shouldn't have thought that in the first place and it was dumb and making into more of an argument, are all making it seem like people are more upset than they are (or were before this turned into a whole thing).