I really think if anyone should be offended by this ad campaign, it would be men. Here are some of the lyrics of the original song:

Oh yes I am wise
But it's wisdom born of pain
Yes, I've paid the price
But look how much I gained
If I have to, I can do anything
I am strong (strong)
I am invincible (invincible)
I am woman

As you say, inspirational stuff. Helen Reddy is telling us that we as women have suffered, and have been made strong through our suffering. And not just strong, but actually invincible. Now that's the kind of thing that makes you hold up your head and feel good about yourself, am I right? I know it does me. Makes me feel like nothing can get to me. Especially not a stupid commercial for a cheeseburger.

Now here's a sample of the "I Am Man," version:

Oh yes I'm a guy
I'll admit I've been fed quiche.
Wave tofu bye-bye
Now it's for the purest beef I reach
I will eat this meat
'Till my innie turns into an outie
I am starved
I am incorrigible
I am man.

Hmmm, now that is interesting. Apparently, Burger King believes that men are unsophisticated jerks that only enjoy eating American fast food. Not only that, but men are disgusting gluttons that if left to their own devices will eat until they actually herniate themselves.

I don't know about you, but if someone said that about my gender I'd be pretty bent out of shape. I might even write an angry letter. :)