Back in the old days when one programmer was programming all alone, the one who always had the complete overview about everything, the one who was acutally writing source code, getting good quality products was easier. Today a bunch of young students with almost no experiences in what they do try to work together. Some start into vacation, the others have to continue their work. Once the one in vacation returns he has to continue the work of the others without even knowing about it, where these are leaving into vacation now. I can imagine that it is close to inpossible to work on quite complex projects successfully this way. At least David Braben himself should know about this.
This is actually a good point.
The things might be complicated even more: someone decided to leave projects, well because of "new opportunities and new areas" or just got bored or just realized how hard to maintain and develop existing stuff. Or some of developers have been left because they are became too expensive.
Anyway the problem is still here: how to maintain and develop the product.
Nothing new here has been invented yet: as books say, write documentation and clean code.
Setting up the processes requires qualification and experience.
Developing features/UI requires qualified personnel either (most likely not students).
Sometimes decisions taken under pressure (release date and such).
ED is a good example of how some of those can fail.