I think it is worth making a distinction between "micro" (what the blogpost is about) and "macro", or "tactical" and "strategic", optimisations.

Strategic optimisations is often basically free if you have domain expertise. It's that easy to know that the business wants x outcome and algorithm y is the right choice etc if its all internal thought processes. Whereas if you don't know enough then you're likely to make very expensive to undo decisions.