Think, why didn't developers fix the malleability soon after it was discovered? It's because there were more pressing issues to solve, and didn't have enough manpower to solve all problems at once. If there were a few more devs on it, we would not be having these issues today.
And I think, really there is the problem. So many new people found about about Bitcoin the past year. Yet I don't see the developer base growing.
The few new people that have a good enough understanding and the necessary skills prefer to develop new alt and to get rich quick over developing Bitcoin.
That really is a good question. Why isn't the number of devs growing ? I mean like 10 people are clearly not enough to maintain all the code. Or are they ?