I totally disagree. I view it like a ski slope. The people below you have the right-of-way. On the MUP, then, people in front have the right-of-way over those behind. Yes, joggers (and everyone else) should be cautious at all times, but as you freely admit, warnings are useless when joggers are wearing headphones. Joggers often wear headphones, there's no law against it, so you should be careful and aware of that fact.

I'm not saying the jogger wasn't an idiot, but if I had to allocate blame, it would go to the cyclist (or at least 90% to the cyclist).