Non-architects often ask questions which boil down to: 'If structural designers make it stand up and interior designers choose finishes, why do people employ architects?' You can respond to this with a whimper or a sneer, a grovelling selfjustification or a head butt, but only looking at the questioner in disbelief, as if to say: 'You didn't mean that to come out, did you?' and politely letting them change the subject, allows you to maintain the mystique which exists around architecture. And mystique is all we have; we are the Wizards of Oz of construction, assuring a client base of Dorothies and cowardly lions that we have mighty powers that laymen would not understand. It is the essence of architecture as a brand.
Those tasks which have been removed from standard practice, such as giving cost advice or detailing below ground drainage, are the parts around which it would be difficult to maintain glamour.
The only enigmatic thing about a bill of quantities is why anyone would choose to work on that rather than just killing themself, and the only mysterious thing about drainage is . . . well, actually there are lots of mysterious things about drainage but none make it glamorous in any way. Consequently, QSs and plumbers are not the subject of glossy publications. It may be easier to get a heart transplant than to find an interesting QS or a decent plumber, but rarity does not, in this case guarantee desirability.
'Why do people employ architects?' This can have only a depressing answer if considered intelligently, so try not to. You make a living from your own skills in obfuscation, flattery and intellectual cost-cutting, and from others' vanity, insecurity and gullibility; just don't tell anyone.