Seems to rest on the assumption that customers want to. But in my experience, quite often the unspoken goals include not only "cheap" and "finished yesterday",

Seems to rest on the assumption that customers want to. But in my experience, quite often the unspoken goals include not only "cheap" and "finished yesterday", but also "without bothering me outside of a fancy kickoff and that penultimate mission accomplished meeting where I bikeshed off through all the shades of blue" That desire can still only be served by its opposite, talking to the customer, but it's a scarce resource, not just something you don't use enough of. Similar to how "finished yesterday" can only be solved by more time, but that can't be time measured in decades.