The bread story is not so good because almost everyone prefers the morning bread and won't wait just for a discount.
This point just confirms the bread analogy; people who like to buy bread in the morning are akin to the people who want to be included in the block chain quickly; they pay a price for this privilege.
The bakery analogy is very correct, including low fee transactions is like making bread at cost/low profit, one can do it, however selfish thing IN THE LONG RUN is to make only as much bread that people will buy at a price that MAXIMIZES profit.
In the future we will have generators that will _not generate_ until there is a certain amount of high fee blocks waiting, and then they will automaticity turn on their massive generation capacity and quickly generate the block. This leaves the average difficulty relatively low, and makes a strong incentive to include larger fees. These generators plainly wont include any low fee blocks, low fee blocks will have to wait around for a charity block.
There will be bank generators that generate regularly, however charge high fees for ANY transaction from the competition. (Just like ATM fees).
The large generators that do this will have a larger percentage of the high fees; they will also not waste electricity on nothing.