I've thought about this, or maybe Atlassian or GitHub doing so, or even GitLab, they're all companies that cater to developers and if they acquired JetBrains it would be a move that would keep them on top of their competitors on a new platform, especially Atlassian and GitLab since GitHub at least has Atom (though it suffers performance issues among other things).
We indeed have no plans to acquire Jetbrains. I think they are doing awesome and we probably couldn't afford them. But also we would like to have a development environment that runs online while allowing for browser based and client based editors. Currently we're looking at Koding https://gitlab.com/gitlab-org/gitlab-ce/issues/12759
This doesn't change the affordability bit, but IDEA is working on a web hosted IDE. They are rolling it out as an online code review tool first, with nice features like goto definition, but eventually going to full run tests or edit code.
JetBrains are in the middle of a daring switch to SaaS which may or may not work; they face threats from all sides; and they're not exactly a "cloud first" business.
I bet if anyone showed up with a huge bag of cash, they would sell.
