You are right, but the problem is exactly that it's a developer tool, and most developers tools are $free these days, so it kinda sets the expectation of price for a developers tool. If Emacs, Vim, Eclipse, Visual Studio (Express) and many, many others IDEs and editors a free, it's pretty hard to justify paying for a developers tools. It's not that it's not worth it, it's just that the common expectation is that developers tools are free.
Sublime Text and Textmate likely wouldn't have existed without many people being willing to pay for them. If we refuse to accept paid for developer tools we are only ever going to get certain types of tools build by certain types of people/ companies.
