[drgath]

> But how can putting this functionality into an extension package be considered a reasonable design choice?

I like the design of Atom, because it allows me to freely compose an editor that does exactly what I want, and nothing more. While multiple panes is a requirement for bpicolo (and you?), I use multiple panes in Atom (my primary editor) and haven't felt the need to resize them. Am I the minority, or are the others? Or is it 50/50? Basically, we don't know until the editor has time to grow, and its community has a chance to dictate what features are required.