With our apps, even though they are fairly standard, we know the biggest risk is rejection by Apple. We hedge that risk somewhat by submitting a MVP (setting the release date in the future so it won't go live accidentally if approved).
Rob's case is special, though, because his app was never actually rejected. I suppose if he'd been willing to submit a MVP and wait the same amount of time in limbo before putting any more effort into it, he could have saved himself all that hard work. But the aggravation of not getting an answer would have still sucked.
It really astounds me hearing about how long new apps and updates can get stuck in limbo, with no feedback from Apple or path to action. So far I've managed to avoid any nightmare scenarios, but every new anecdote I read makes me increasingly anxious that one day, that time will come.