Sorry but to me this hears similarly too "coders do not care about why runtime speed is slow, they just want it fast". You cannot get gut runtime performance without understanding the performance constraints of data structures and algorithms you use, Similarly, when using Scala, you must be aware of the performance cost - in compilation time - of the various features and act accordingly. So yes, what can be fixed should be fixed - but I am happy with having the possibility to trade ocassionally a powerful feature that will make my coding simpler for some unavoidable compilation delay. (Though I would of course prefer the compilation to be instantanous.)