It's a travesty, I know. Lingerie pattern maker here. The main reason is likely due to sales, limitations in design and limitations in space. Larger cups tend to have LESS space between the breasts which makes front close difficult to neigh impossible. There are also design limitations which differ depending on if it wired or wireless. The majority of the stuff on the market seems to be aimed at the post surgery crowd (wireless), retirement crowd (wireless) or plunge, cleavage crowd (wired).