Rather like Intelligent Design [ No link love for those idiots ] or the Sapir-Whorf Hypothesis [ Wiki ], morphic resonance has a certain amount of common sense appeal, at least until you understand enough of the science around it to realize that the idea left the EZ-Bake a little too quickly.
However, at least in its reduced state morphic resonance has certain obvious sociological and technological applications. Specifically, once people know something can be done, they will find a way to do it again. Consider the hydrogen bomb. The Americans built the first one, with a great deal of German know-how. That showed the Soviets (and others) what was possible, which crystallized their resolve, their funding and their research direction.
There's a cultural assumption embedded in that idea, though, which is that there is nothing inherently unique in any specific person. In other words, with enough training and the right talent, another person can reproduce the effort made by the original hero. (In a different context, consider Roger Bannister and four-minute mile [ Wiki ].)
So Prometheus brings down fire from the Gods, and anyone thereafter can wield a burning brand.
Except I'm pretty sure this is a Renaissance, or possibly Enlightenment, mindset. The very idea of a causal chain, which is required in order to seriously attempt to reproduce someone else's achievement, is essentially a modern concept. The concept that anyone can do anything seems to stand squarely contrary to such classical ideas as the Divine Right of kings, or the god-touched hero. Certainly the pre-modern perspective is still embedded in our culture -- consider the truism "Only Nixon could go to China." But that's a political perspective that borders on a joke, not a serious expression of a key man theory of history.
What kind of culture do you have when it's not inherently obvious that any achievement is completely repeatable? What kind of culture do you have when some people have special powers by virtue of birth or heavenly favor which are simply not possible for others? Could someone other than Beowulf have slain Grendel?
To me, this line of reasoning has some obvious contemporary political and cultural applications, but in the interests of not ranting, I'll leave those aside for another time.