For things like nightfalls, yes there is really no reason for the lack of match making. Although alternatively they could improve the guided games system, which they really never have for some stupid reason. It is a system that could work great if they actually gave some kind of incentive to the guides, but Bungie just can't seem to figure that simple thing out. As for missions like whisper, I think the main issue with making a match making system for that is the general anger it would lead to on things like the forums. People would instantly run to the forums to make angry posts about how every in the match making system is an idiot and a noob that can't get through the jumping puzzle or can't kill, or both. Although again this could be something that guided games could be used for, but sadly bungie doesn't know how to use their own ideas. For the zero hour they could have easily made it so that those who guided other people through were given something like 5 percent towards their catalyst each time, there by encouraging far more people to get others through, and getting their catalyst just a little bit faster. Again the majority have absolutely no problem with making these systems better, or implementing them in a more general manner.