Earlier quoted context omitted.
That's how all their IDEs work. It's all the same software with different sets of allowed plugins. From where did you get this idea -- basic use? It most certainly is not this to as great a degree as you might like to think. Source: JB employee.
Could you get into more detail please? From my (brief) experience with your products I think the differences are indeed mostly in the plugins, apart from cosmetic / UX ones, like different keyboard shortcuts (which by the way never made sense to me). There's nothing wrong with selling sets of plugins by the way. I don't really get why it must be different IDEs though.
Uhm, I've tried using Ultimate for Java and Rust. It wasn't pleasant at all. Different IDEs make total sense to me.