It is much simpler than that. Dynamic (cone) speakers are more popular because they are small, easy to live with and there are hundreds if not thousands of them available that are less expensive than just about any planar system, magnetic or ESL. Ribbon speakers have just as wide a sweet spot as any dynamic speaker as do ESLs that are not flat but curved in some fashion. Ribbons and ESLs have much better transient response than dynamic speakers because the moving part has much lower mass and every molecule of the diaphragm or ribbon is being driven and controlled down to the molecular level. Dipole speakers which includes planar magnetics and ESLs, limit dispersion in very useful ways and when you make them line sources this effect is better yet. Not that you can't get a dynamic speaker to perform well but most do not perform as well as the better planar magnetics and they have not got a prayer against a line source ESL. Horns, because you have better control of dispersion and they are a better impedance match to air like ESLs should be the ultimate point source speakers, ESLs the ultimate line source speakers. Cones, domes and such belong in a museum with Edison:)
(Just intentional inflammatory rhetoric to bring out the gremlins.)
(Just intentional inflammatory rhetoric to bring out the gremlins.)