The Most Important Decisions are Non-Technical
While it's fun to discuss whether an application should be implemented in Ruby or Clojure, to write beautiful and succinct code, to see how far purely functional programming can be taken, these are all secondary to defining the user experience, to designing a comfortable interface, to keeping things simple and understandable, to making sure you're building something that's actually usable by the people you're designing it for. Those are more important decisions.
Facts. Same thing applies when choosing what problems to solve and how to solve them. Ever see a team rush to add a new bit of tech to their process, hoping it'll solve a collaboration problem for them without anyone needing to have any difficult conversations with anyone? Mmhmmm.