Think it's just a psychological thing based on price/premium
Just comes down to premium charged by dealers unfortunately, plus the fact a 1/4 which is still premium heavy,is within a large number of peoples budgets. Price them right and I and most other's will buy as many as i/we can, whether from here or a dealer. I like the size and its more visually enjoyable than a 1/4 any day.
@Paul recently had 2 x 1/2 Krugerrands up recently for approximately the same price as a full krugerrand. I bought them because in my tiny mind, 2 is better than one if price isn't an issue.
Then he went a decided to offer 4 x 1/4 Krugerrands at approximately the same price as a full Krugerrand, yep you guessed it..I bought those too🤣 because 4 is better than one.
1/10ths I hate and ive tried a few times to get into them, not just because of premium, but when you have to take a photograph of a coin ...then zoom in to read the date,its an issue.