I am struggling with this. As far as I can say that you are saying you looked at a large code base *once* and you found that it was complicated and you didn't understand it.
Is this not true with most code bases? I mean, I can look back at my own code from a while back, and it takes me quite a while to work out what it is doing. And long-lived code bases can, ironically, be particularly problematic.
The ultimate problem here is the funding problem. Free software is much more adaptable because you don't have to tell anyone what you are going to do with it before you do. But someone still has to pay for it at some time. The strange thing is that people and companies have roads coming to their doors which are maintained by the public, but the same is not true of essential software like OpenSSH.