Frankly I'm amazed the HTML way of verbose writing still stands after all these years in a fast paced industry.
By the way, Jade is in the process of being renamed to Pug because of a naming conflict with someone who holds the rights to the Jade name in another context.
Do one thing and do it well, pretty much.
EDIT: editting since I can't reply to child post.
The thing is, if jade does it well on its own, then all the other tools won't profit from it. I believe jade should focus on outputting easy to understand, well-indented HTML.
When debugging HTML problems (missing attributes or whatnot) in development, I always disable any kind of minifiers. If jade implements a minified output, it would need to be optional, further increasing complexity.
If minification is a build step, I can just disable that step. Easy peasy.
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.
Whether that is really important is another question; probably in the big scheme of things it's not worth worrying about. But I wouldn't dismiss it without knowing for sure that the costs in complexity to Pug are actually significant. That would require someone who knows the codebase to comment.