So, I should be OK to use my most precious asset -- time -- on an investment in a dead-end technology, because that investment could possibly, maybe translate (in some reduced way) to me being able to use a different technology later on that is not a dead-end technology? How about I just invest directly in technologies that have a payback and not try to cram the entirety of all software engineering systems into my brain. I already have an unending amount of things and systems to learn in s/w, why shouldn't I prioritize the learning process towards investments that have the best paybacks.