Not the parent but I have the same reaction, and I wouldn't describe my experience in big IDEs as "comfort", just less pain. I use them with Java only out of necessity, and only on huge projects I didn't have a part in designing up front.

Every other programming language I've used a lot of (spanning from assembly to lisp) I've found it most pleasant to work in vim, even in large projects. I suspect the only other environments I'd want an IDE would be for iOS development and C#.

I found Vi to work perfectly well for C#.

Visual Studio would have been better, if I could have got a decent Windows desktop to span both of my monitors. But since my employer at the time didn't want to get a Windows PC or get a Visual Studio license for this Windows desktop application project, Vim + Samba + SSH were a workable substitute.

I don't know if it's still there, but at one point (some?) MS licenses had an audit clause that would allow the BSA or MS to raid your employer at their expense. That could be one reason for a non-MS shop not to want to get any MS licenses.

Java and C# were both designed to be used in language specific IDEs (C# inheriting that from Java). Using Java outside of a Java IDE is insane.

C, C++, Python, Ruby, JS, Erlang, Perl, etc, just require a relatively sane text editor, no full scale heavy weight IDE features needed. So, yeah, vim does everything I need there.

"Vanilla" C++ is one thing, but when it comes to using comprehensive frameworks such as Qt or wxWidgets, I guess you have similar reasons (to Java and C# with their "batteries") to use IDE.