So I think one of the things best avoided in life in general is extremity, in all its various guises. No single technique should be followed like scripture, but rather incorporated into ones toolkit and used where appropriate. Building top-down will get you where you want, but risks fragile underpinnings due to a lack of cross-cutting architectural guidance. But, on the other hand, bottom-up might get you the best foundations at each layer but ultimately deliver nothing of value to the users. In practice it's necessary to take a balanced approach and, of course, mistakes will be made and experience will become the guide. Like you I definitely employ the "meet in the middle" approach in practice, but what SICP taught me is how to think about starting at the top, that is, to build upon wishes.