Generated content generally looks generic. For example, looking at the dungeons generated for a roguelike game such as those in the Diablo series, you easily get the sense that this is just a bunch of building blocks hastily thrown together with little finesse [..] Most generated levels lack meaningful macro-structure and a sense of progression and purpose. [..] Compare this with the often masterfully designed levels in comparable games such as those in the Zelda franchise.
Procedural Content Generation: Goals, Challenges and Actionable Steps - Togelius et al. (2013)
Please note that this is work in progress! The code is far from production ready and huge structural changes will occur.