Micro-payments have come to the Internet. Just not through credit cards. Look at any "Free2Play" online game and you can find plenty of micro-payment variants.
For a non-game implementation, look at Amazon coins. Once you overcome the transactional costs of traditional methods, it's very cheap - fractions of a cent to process. The only efficiency problem with private currencies is the breakage around conversion - usually you can't buy "just one", and if you don't use up all the converted private currency, you strand that value in the economy that uses that private currency. So it only really works for ecosystems that are "large enough".
BTW, I agree with everything else you said. Content providers have an inflated sense of their content's worth, and need to reset their pricing models.