Embrace your crankiness I say! I give plenty of lectures to my boys - once so effective that they ended up dancing around the living room chanting "bad McDonalds". Didn't last, sadly - DH isn't quite as adamant as I am. They don't really like the food, but the toys get them.
Health, health and health, by way of reasons. I'd be outraged too. And companies that already market aggressively to children really don't need additional help from the government. Do you know why the state govt. is giving them the promotional opportunity? Has Maccas made a significant financial contribution to something?
It's such a cheapo thing to offer too isn't it. There are probably all sorts of more interesting/creative offerings they could have come up with without breaking the bank.
Sorry, not up to much by way of considered response (still in post-tantrum trauma) but best of luck!