Why is McDonald's a greedy corporation?

...Before any of you guys state the obvious, I know that they are in it to make MONEY..BUT have ever thought about this? Fact: An average McDonald's store grosses between $800,000(bare minimum) and upwards to $2-$5Million Dollars(more common) a YEAR?!?!?..Im all for making a lot of money sure!..but a typical McDonald's employee only makes $7.25-$8.00 an hour which turns out to be around $320 dollars BEFORE taxes a week If they work 40 hours (store managers aren't generous about giving alot of hours in the 1st place)..but isn't that ludicrous?!?!? I want YOUR opinions...thanks in advance!!!