The point here is that the focus on this particular issue is making everyone think there is an unusual systemic problem here when in fact the same problems exist all over the open source community and for better or worse distros are expected to deal with them and prevent upstream compatibility issues from affecting end users.
KWin uses relatively more driver features than Compiz, and uses features which were only recently implemented in the drivers. That resulted in some pain for a while, and the pain will probably continue for a while longer until the two components and communities "get used to each other", but the same thing happens in many places every day.
Can the situation be improved ? Absolutely. Whoever is responsible for managing the entire GNU/Linux/X/Mesa/Gnome/KDE/... stack is obviously not doing their job well enough. Oh wait, there *is* nobody responsible for that other than some folks at distros responsible for making *their* combination of components work together and some technical leaders trying to drive improvements into the entire stack... maybe that's the real problem here ?
If we want components to work together then they need to be planned and managed together from day one, and right now the incentives don't encourage that kind of behaviour. Beating on individual development communities after the fact is not going to help, although it is probably more fun than television, and is more likely to just harden positions and reduce communication in the future.