Text editors and terminals have a bunch of similarities: They're completely customizable, you can change and add key bindings, and they're scriptable. Those two features make it really easy to add my own features to my terminal and text editor. But it's really difficult to add features to my web browser.
Here are some examples of features I want to add keyboard shortcuts to in my web browser:
- Opening the source code for the current web page in my text editor.
- Copying the URL that's open in each tab to the clipboard.
- Move a tab to a new window.
- Start a new blog post for my Jekyll blog with the current URL.
Text editors and terminals make adding these kinds of features easy, but they're not easy to add to web browsers.
If there are web browsers that make these kinds of features easy to add then I'd love to hear about them! But that still leaves the question: Why are these types of features important to web developers in their terminal and text editor, but they aren't important in their web browser?
Without doing any work, I can:
(yy) Yank the URL of the current tab to the clipboard
(gD) Move current tab to a new window
With some work, it's not impossible to get the features you want, or something close.
What about a compiler, linker, and other related tools? Also, I don't consider a web browser to be an essential programmer's tool at all. I often go days without using one in the course of my work.
But maybe I'm being a little unfair here. From the rest of your post, I think that perhaps you're not actually talking about all programmers, but rather developers working on web-related things.