why doesn't apple make more different devices then? I guess they have been trending that way.. But still, how does "compartmentalizing" make up for 30 different

why doesn't apple make more different devices then? I guess they have been trending that way.. But still, how does "compartmentalizing" make up for 30 different production lines and whatever else can't be parallelized? Like the tiny differences the other reply noted, what is the difference in a consumer who picks the 3 mm bigger?? Do these "segments" of the market exist naturally or is it manufactured to some degree? ie If one year they suddenly consolidated down from 30 to 5, what % of customers would they really lose?!