I don't think it really 'matters' to humanity in the sense that stoppping nuclear proliferation 'matters', I just think it's very interesting. I mean, most of us are at least slightly interested in the study of history, whether for inspiration, life lessons, knowing where institutions and customs came from, or just for wanting to understand how the world we live came to be from a human perspective.
Now, say what you will about Christianity, but it did become the world's largest religion in a relatively short period of time, and the teachings of a certain Galilean preacher did come to be regarded as the word of God for millions (even billions) of people all over the people. I don't think anyone can truthfully say that finding out how this came to be is not even a little bit intriguing and interesting - though obviously the extent will differ from person to person. That's why I really like to learn about Early Christianity, and the history of other world religions. I find it incredibly fascinating.
Now, I think the reason a lot of scientifically literate folks (and I'm one of those myself, so I know what it's like) tend to look down on history is because - as you allude to in your post - there are different standards of evidence at work.
In hard sciences like physics or chemistry we can usually test phenomena as many times as we like, and in pretty much whatever quantities we like. If we missed something or are not 100% sure, we just go back and do it again. In sciences like history, things are obviously not that simple, and we can only work with what we have. Sometimes that means having to draw inferences from very limited amounts of source material, and sometimes it means recognising that it's impossible to draw inferences at all. Even when historians talk about a multitude of sources for an event in the ancient world, we're usually not talking about more than half a dozen - we consider that a lot.
It's probably for this reason that historians and history enthusiasts often face the charge that they can't prove x or y. You for instance note that nothing Jesus ever said can ever be 'proven'. Well, OK, but historians don't prove anything most of the time: what they do is contrast and compare evidence. Depending on your definition of proving, we can't prove that Caesar said anything at all either. We can't prove that Hannibal defeated the Romans at Trebia. We can't prove that George Washington is the founder of the United States. In fact, unless we have explicit video documentation (which is obviously very rare) we can't prove anything about pretty much any figure who has ever existed on this planet.
The thing is, the methods of historical analysis don't require us to prove anything in that manner: they just require marshalling evidence for your case, and trying to make a better case than competing theories. And some cases will be better than others; and some are so well supported that it becomes silly to try to deny them.
Using reasonable standards of historical analysis, I think we can make a case about who Jesus most likely was that goes further than simply seeing that he's a guy who got crucified. And I think people can learn a lot from doing so.
In fact, I think I could argue on that basis that for the general public, a workable knowledge of history and understanding how historical skepticism is performed, is even better than understanding how science works and what principles science uses. Though knowing about both is obviously preferable.
I agree with you there Matt. The history is very interesting indeed. I totally understand why people would want to see how jesus went viral so quickly and so far spread. What I also find interesting is that the Muslim faith seemed viral maybe even quicker than christianity and at least as far spread. What all this leaves me wondering is, who the next viral deity/super prophet will be?? Maybe we should start another thread and let people put their own ideas about that out there? lol
Having a workable knowledge of history is desirable for the masses, what worries me is their ability to discern fact from fantasy where supposed divinity is implied. One thing history DOES prove to me, and that, is that it repeats itself :(