Not sure how magical your automatic optimizations are - but my experience does not at all mirror yours. i've certainly had to hand-optimize queries to improve performance, on top of the query already being automatically optimized. Removing unused data, tying across custom relations and moving things into different forms of caching are all quite manual efforts I've done plenty of. So, not sure how "less common than you'd think" holds up to scrutinization. I'm just one counterpoint.