Long years in software do rigorously teach that complex things take long. Longer than you expect even including this rule. Or don't work at all. This non-proven rule-of-the-thump need not apply to self-optimizing AI but could at least be seen as an effect explaining or at least affecting the judgements of experts.
Added. I realize that this is basically a TLDR of Copla's comment.
http://reducing-suffering.org/predictions-agi-takeoff-speed-vs-years-worked-commercial-software/