I think Auxen1 is right about the corporate politics but overstates the case in practice. It is a fact that within the fast food industry, independent McDonald's owner-operators represent an unusually high percentage of total restaurants compared to other chains; many other chains have deliberately kept the proportion of independent franchisees down precisely so that they don't have the rambunctiousness McD's has sometimes had.
The franchisees have sometimes been a source of ideas, especially the bigger groups (like California's o-o group or MOCNI here in Chicago/Northwest Indiana). The Egg McMuffin was invented by a franchisee; the "Mac Tonite" campaign of two decades ago with the lounge singer moon came out of the California group, fed up with what they saw as lackluster advertising coming from corporate's ad agencies. I'm sure there are many other examples.
On the other hand, let's get real. These guys bought into McDonald's-- at great expense relative to launching a stand of your own-- because they know what they're getting, a brilliantly refined and optimized system that is a sure moneymaker. Unlike, say, Burger King, which took advantage of government minority lending programs in the 70s to open stores anywhere (and collect a piece of your tax dollar action), not caring if they promptly closed, McD's researches locations carefully, buys land whenever possible, delivers a consistent level of quality (personally I think the relative gap between the best McDonald's and the worst is far smaller than between comparable burger chain outlets), and generally over 40 years has done outstanding marketing whose proof is in the chain's overwhelming success. You can hate them and everything they stand for, but you can't deny they're good at it-- and the o-o's know that too. And while they may rebel at this or that, they may cause migraines in Oakbrook, they're not going to tear it all down. They exercise their independence when they feel corporate isn't serving the strategic goals of a fast food giant as well it could be, not because they suddenly have new goals. Their "independence" is within a very narrow realm, relative to the whole world of food.