[Re. Why space aliens are supposedly visiting Earth]
They want our DNA?
Well, I'll tell you something you don't want to hear. You wonder about the actual truth behind this stuff. But you'll scoff at the actual truth, because its something you don't want to hear. You already have your glorified pre-assumed ideas of what it must be all about. But the truth is not like you imagined.
They want children of their own. But they don't have women, and were never intended to have women or children. Only women can be reproduced with. The earth is the only place in the universe that has women.
We're scum to them. Useless. Not worth their time. Except, they feel they've been screwed over. Women and children were given to scum like humans. But these good things were not given to high glorious beings like themselves, who feel they're much more deserving.
They can reproduce with women, and have in the past. But its been forbidden for them to do so. Dire, dreadful consequences for reproducing with women that they certainly do not in any way want.
They want our DNA (altered by them, of course) to reproduce with women. Because it gives them children. But its not technically reproducing with women, in the traditional sense. So they're able to get their children, and work around the penalty for it.
The children appear closer to humans to us, than the visitors. But there are aspects about them, both inside and outside, that are very "not right." They're beings that should have never existed.
Do the visitors deserve to have children? Are they wrong for acquiring them in the way they do? I don't know. But I'm not the one to judge.