Do they do it on purpose?

I was thinking as I was performing my Skeye Pad mod...why is it that every handheld and laptop, which nearly all seem to use 18650 lion batteries...why don't they build them simply like a flashlight...where you can unscrew something and drop in a new battery both easily and inexpensively.

I mean is the idea behind a battery pack something they do on purpose to sock it to the customer to make them have to pay more when the old batteries deplete?

18650s are used in so many electronics these days that there is no reason to force customers to have sealed manufacturer sole proprietory battery packs...

Write a letter to Apple Rich, they're bound to have a good excuse to offer on this subject.