XSLT got an unfair shake. Yes, XML is ugly, and verbose, and painful to write code in, but the ideas were very good. Most users never understood the processing model or the declarative/functional nature of XSLT, and so tried to write procedural code with it, with predictably nasty outcomes (hint: <xsl:if> is almost always a code smell). But those who did get it, could use it to write some pretty elegant little programs.

I liked XSLT for XML to XML but using it for creating HTML was a nightmare.