People curb their wheels as it is, and by using stick-ons for the outer side, at least the weights won't get scraped off. Also, some feel that wheel weights are ugly and would rather drive unbalanced than having visible weights.
Modern balancers usually have the option to hide the outer weights behind the wheel spokes, which while not 100% efficient (requires more weights) caters to those who think that it's better to look good than to feel good.
Anyway, a large diameter wheel is actually easier to balance, in a way, than a small diameter one. A given wheel weight is more effective the farther from the axle center it is.