It's incredibly convenient to just install an extension, as opposed to an external program, configure paths and the like.
Edit:
Jesus guys, enough with the white knighting for Atom. I think you should use whatever editor you want, I'm just countering the point that it's not bloated because it's modular.
You can spend your life proving that your editor is the truth, or you can get on with it and build something awesome.
As long as it's not so big it becomes inconvenient to download it (IMO in the 10+GB range) I simply don't care about it's size, it doesn't effect me at all.
Use what you want to use, this field has too many holy wars already.
But does it really matter? We are not developing using potatoes. Even a 5 year old computer bought at a department store should have no issues running Atom.
The more useful metric would be, what's the actual performance like? I couldn't care less if it used gigabytes of otherwise unclaimed memory for caching. Unused memory is wasted memory.
Atom has more potential, as it embeds a full web browser. That potential is mostly untapped right now, but it is there.
Typing at once in different parts of the code would be a huge boon to pair programming (that isn't even possible with in-person pairing, yet). Imagine being able to jump in and fix a typo while your pair keeps writing the next line.
There's no product that does this well enough for reliable daily use across a range of project types, but I can dream.
(I'm not affiliated, just have used it for pair programming before with success)
At least it's possible...
Because source code is text. Text is edited using a text editor or an IDE.
(Hint: those are all visual or hybrid textual/visual programming languages.)