I agree with your first point. Pre-processors, especially in the CSS realm, are so intuitive that there should be negligible training overhead. I believe they

I agree with your first point. Pre-processors, especially in the CSS realm, are so intuitive that there should be negligible training overhead. I believe they should be used past a certain threshold. I disagree with your second point, however. Single page applications are good for pages with a high amount of short, repeated interactivity where concurrency and frequent status updates are prioritized. However, there are plenty of applications that I use where I prefer to have a workflow built on discrete states (pages). They typically perform better in terms of rendering time and latency, both in terms of request and user action. (Just compare reddit's mobile beta to their previous mobile site. I still type in /.compact because I can't stand the new SPA.)