Software development is a profession where the least you need is a computer with a notepad and a compiler (or interpreter). Yes, I can create a hello world using only this (as done in every intro to programming course). Still, I can't imagine working on these gigantic problems with humongous interfaces and complicated interconnections without having an IDE that helps me autocomplete, marks syntax errors, and can give me documentation about the methods I'm trying to call.
It's all fun and games when looking at someones else code before you notice that it's the code you wrote a few months ago. Now you know you have to fix that block of code, and you send it for review. But what's this review?