The thing is that editor scripting interfaces (vimscript in particular) kinda suck. I'd much rather have the essentials as built-in features in the editor. For example, surround.vim is kinda nice feature but it doesn't play nice with undo and repeat.
Most text editor scripting add-ons fall into two categories: 1) core editing features (like surround.vim) or 2) bringing IDE-like features to the editor.
Things that fall under category 1 generally work better when they're implemented in the editor core. Things that fall under category 2 could mostly be implemented outside the editor, e.g. using tmux key bindings to open a new window to run the compiler in and then send the output back to the editor. I don't really want the editor to have a terminal emulator and windowing system to launch the editor in.
There are plenty of proper IDEs out there, there are plenty of scriptable editors out there which have (mostly half-baked) scripted IDE-like features out there, as well as bare bones editors with no scripting. I'm not gonna argue one is better than the other, but there's no reason every editor should have a scripting interface in it.
I have used programming tools in every category and they all have their merits. I had a fully pimped up Vim setup with lots of plugins but I eventually abandoned them as they were more trouble than they were worth and now I have a very bare bones setup with minimal customization.
So yeah, I don't think scripting is an essential feature in a text editor, and I'd much rather see the effort spent core editor features polished than a scripting interface.
As for "my specific needs", I need a good text editor first. I've used about a half dozen different programming languages in the past year, and no editor out there would handle all the "integrated" features to all of them gracefully without a lot of customization.