People who are programmers or have any idea how it works are not complaining. There is a very common sense explanation to this. First, you need to understand that Halo 3 and 4 and the Halo 4 engine was ported to x86, which takes time and resources. Then you have to realize that all of these games were collected and then put together with their original code. If your a programmer you understand that when deadlines are set you hack shit together to make it work. This is not just for games this is for every piece of software you have ever used even the shit that works. This hacked together method has probably been done for every halo game, and every game in general. Then you have to take in consideration that programmers are lazy and that good comments were probably never done, because once it ships they had no intention that the code would ever be changed again. Then on top of all this they then have to take all the shit code and hack it together again to make it work for all games. That's a feat of all feats tbh. Then when the game actually shipped the hacked together code didn't scale well. So they went back to their hacked together code tried to get it to work and nothing they did worked. So they went back to the original code for each game, then realized that most of it was hacked together and no notes from the previous writer is there or its shit. So while it worked for that game it doesn't play well with the hacked together code and you just can start messing with original code, because well it breaks shit. So now 343 probably has to go back to each original code and redo it so they can then hack it together to get it all of it to work, mind you without breaking anything. And if you think that 343 has great programmers and they should get their shit together, let me shed some light. No one ever wishes to be a game programmer unless your super passionate, especially when programmers are in high demand and there is way more jobs to be lazy at that pay more.

If you really want the game to work, you probably want to demand that each game be separated. This of course will easily fix everything but it totally wasted 343's money and time. Plus, the whole lure of the MCC is to have MM for every Halo game in one place. This is feat is not easy especially considering probably the original developers for each game are long gone. This is why for the most part Halo 5 works fantastic for being 11 months out.