[tux1968]

Yes, that all makes sense. But there is also a cost to such a design. To my mind, doing it well means outputting optimized code.

Edit:

Worrying about the fact that Jade/Pug optimizations won't benefit others completely misses the point. Any improvements to its parser wont help anyone else either. The question is how to make the best tool for the job.

Perhaps the inefficiencies of outputting sub-optimal HTML don't matter much in reality. But if optimal html output was easy to do we would expect it to be done, right? So the only question at all worth considering is how difficult it is to achieve optimal HTML output.

My gut tells me that better output can't be that much harder, but I have never looked at the code at all so I may be dead wrong.