Seems to me that you were being interviewed by a technocrat not a business person. My reading of the interview suggests to me that you are a person who can see an opportunity for business improvement and implement a valuable and reliable solution.

If this project is representative of how you look at the world, then maybe you should be focusing on how you can solve business problems. That is you are valuable for that level of insight and execution. Arguing over Java 1.7 vs 1.8 and PHP vs AngularJS doesn't increase business profits and doesn't recognise your true skills.