Einstein was the first person I'm aware of to whom this idea is attributed. I'm not convinced of its effectiveness myself. I tend to the view that a goodly chunk of people who do this are simply either enormously pretentious, or just not interested in clothes. Both are especially common in the tech industry, a field so square and conformist that they think it's still an act of rebellion not to wear a tie.
I think there are more than two explanations, Edward. From experience it certainly does save time and effort. I would have thought wearing a tie is the act of rebellion these days since I can't think of many jobs where a tie is still required. Maybe that's just Australia.
My favorite watch maker (long gone to God), a specialist in servicing Brietling, Omega and Rolex knew everything about watches and could fix anything. What did he wear? A black Swatch. He didn't care to wear anything special, he was happy to understand them and appreciate other people's watches.
For me, ditto for clothes. I have established my preferred look and never need to think about outfits or matching items but this doesn't mean I don't appreciate other people's clothing.