[glogla]

That's not really a question.

But if you ask why they choose to, they mostly don't have that much choice. Often, rules say "publish in magazine with impact factor at least X" and that's it. The publishers are the gatekeepers of that.

[refurb]

So what the journals provide in exchange for money is impact factor?

And what do you mean “gatekeeper”? It’s their journal and they created the impact factor, no?