Except it's not irrelevant, because the user doesn't care whether it's capacitive, infra-red, or little gnomes perched on top of the screen translating your finger movements into magic spells. Apple didn't invent capacitive screens, nor did they invent multitouch. They packaged them cleverly and used what leverage they had at the time to force the price down.
You're making the "graham invented the telephone so there was nothing invented to make the cellphone" error.