While vim is very cool, there is certainly a lot of room for improvement. vim's codebase doesn't look like something that I would like to hack, and don't try to tell me that things like vim plugins or vimscript are supposed to be the best that we can ever hope to do.
I'm not trying to tell you anything about the codebase, vim plugins, or vimscript.
I'm trying to tell you that it's probably a waste of your time to agonize over text editors, when there are two very powerful editors available to you, with decades of development and refinement, millions of active users, hundreds or thousands of contributions of plugins and scripts and support tools, copious documentation and examples, and the tools you need to embark on any text editor task you may have without ever feeling limited by the editor (assuming you have learned your editor).
Do you want to work on your software, or do you want to work on text editor scripts? Sure, sometimes you need to write a macro or script or something...but, I can count the lines of vim code I've written in my entire 20+ years of programming on my fingers and toes (if I count vimrc stuff, it'll require a few other people's fingers and toes, but it's still statistically zero compared the amount of code and docs I've written in that time).
I'll leave it to Bram Moollenaar figure out how to improve vim. He's added Python support to vim years ago. Is Python really insufficient for you? I've never needed it, but if I were making something big for vim, I'd probably look into it. But, again, I'd rather be working on the stuff I'm passionate about. Editing text is not a problem I'm excited about; if it's your bag, that's great. But, for the rest of us, it's just a form of procrastination to fiddle and futz around with new tools when the old ones are more than sufficient (and probably superior, on the whole, to new ones...sure, TextMate is super-badass and awesome; but it's missing tons of capabilities that vim and emacs have, and you'd probably be better off learning how to maximize your efficiency in those more powerful editors, than learning new tools which will come and go).
the problem is that there's a lot of accumulated work that has gone into vim at this point, and none of the attempts to reproduce that atop a cleaner, more modern codebase ever went anywhere. emacs's evil mode[1] looks like the most promising current alternative.
