A while ago I was really against using WordPress for anything other than a blog, because you know, it's blogging software. Recently I've been playing around with writing plugins for it though and am starting to come around.
Here's the thing: what is the one piece of software that you could run on almost any hosting provider in the world? It's WordPress! Whats that one piece of software that you could run for less than $5 a month as a website? It's WordPress.
The indie hackers are a scrappy people, given it's ubiquity, low cost and the amount of help you can get with configuring plugins or writing your own custom PHP it's a perfectly good way to go.