Is XML all that bad? Sure, a lot of people have an irrational hatred of it, but there are lots of things that people hate, and that doesn't mean they're dreadful. One reason so many people criticise XML is that it's so widely used -- more people are familiar with XML than have even heard of YAML. (And, dare I say it, some of the people* extolling the virtues of JSON are trend-followers who regularly claim that whatever they learned about most recently is the bestest thing ever.)

The advantage of XML, from the point of view of a human trying to work with it directly, is that you can get validating editors that will flag up any mistakes as you type them. Typo in a tag name? A good XML editor will flag it up and may even be able to fix it automatically. If you're using YAML, JSON, etc, then the first thing you'll know about it is when your program chokes on the invalid input.

* I'm referring to the wider Internet here, not the people commenting in this thread -- all the people posting here so far are clearly familiar with all the options and are presenting informed opinions.