I would love to see a reduction in the constant stream of required security updates
That would probably mean substantially less response and development, and maybe even a at some point (shudder), a price tag on WordPress.
Just to offer a different perspective, I see the frequent releases as very positive evidence that the open source nature of WordPress adds to its refinement and security. The community at large is much more likely (and if you spend any time in the forums, you can confirm this), to inspect, detect, report, complain, and on occasion offer constructive revision of WordPress code, as well as supply an ENORMOUS amount of feedback when something is amiss. I have noticed that a large amount of that feedback is related to feature requests. It goes without saying, that anytime you introduce or change a feature, you also introduce the possibility of quirks, bumps, compatibility issues, and yes, possibly new opportunities for attack and exploitation. I suppose it's a trade off. Huge popularity and a gigantic user base means WordPress has a higher rate of inspection and detection. I see it as a good thing, and the Dev's seem to respond very quickly.
I suspect that if less time was spent adding new features and more time was spent improving/double-checking security, this situation would improve. As a developer, though, I totally understand why devs might rather add more features
I think you hit it right on the head. Every time they do (respond to feature requests, or add new ones), the discovery and refinement process has to start all over again. Long term support projects usually don't focus on providing a lot of new features. They usually focus on security aspects and refinement and stability of the existing product/program for the length of the life cycle. I like WordPress because everybody has an eye on it, and it responds quickly. Try to get that with most proprietary software (anyone use a "Windows" Operating System?). Sure, WordPress upgrades can be a pain. They bug me too, (and I have biffed a couple of them big-time!), but I consider the reasons and slog through it anyhow.
...plus, it keeps my learning curve from flattening out!
Just another opinion.