It was the bulk of full moon clips alright, but not for carrying that did them in:
The ‘half-moon’ clip evolved from a ‘full-moon’ clip design originally invented by S&W for rimmed cartridges in their ‘Top Break’ #3 revolvers in the latter part of the 19th century as a form of what we know today as a ‘speed loader’.
The original intended use was never put into production however. Probably because Smith didn’t have much luck obtaining Army contracts for their revolver. A good idea languished for 30 years or so until the “The .45 Hand Ejector U.S. - Model 1917” was designed to chamber the 45 ACP rimless round. Why then did Smith & Wesson invent and patent the half-moon clip?
Very simple as it turns out; the military correctly concluded that pre-loaded half-moon clips could be packaged much more efficiently than pre-loaded full-moon clips. Which Smith, at the request of the Army allowed Colt to also use free of charge. Alas, the full-moon clip was once again relegated to the back burner of firearms ingenuity. Only in the more recent past, after 100 + years since its invention, has the currently popular full-moon clip finally gained its full due.
The half-moon clip was patented in 1918 (application filed August 15, 1917) by Joseph H. Wesson, one of Daniel B. Wesson's sons, who also designed a machine to load them. He also designed various full-moon clips and even a quick loading carrier for 24 cartridges.
Factory racks of 1/2 moon clips prior to being loaded: