It’s not, though. Git is a means of distributing content, not the content itself. The thing analogous to PornHub’s porn on GitHub is the source code in the repos hosted there, not Git itself.
Git is a DVCS. GitHub is a place where DVCS repositories are hosted. There are many other places where DVCS repositories can be hosted, but GitHub is the most famous one… Porn is a type of content. PornHub is a place where porn is hosted. There are many other places where porn can be hosted, but PornHub is the most famous one. It’s a pretty good analogy.
There are many other places where DVCS repositories can be hosted
I mean… Everyone that’s cloned the repo has a full copy of it. You could clone it directly off someone else if you wanted to.
Sure… and you could pass around porn on thumb drives. But, having a central website where you can browse public repos and clone the interesting ones is a pretty key part of Open Source / Free Software development.
A key difference:
If you rely too much on PornHub, you’re never going to get fucked.
If you rely too much on GitHub, you’re eventually going to get fucked.
Git = bittorrent
GitHub = the pirate bay
Code = content
Even that’s not the perfect analogy but it’s better than the OP.