But, after pancaking dozens of cities, a rag-tag group of humans cause each and every one of the alien ships to crash, the thousands of people who were no doubt crushed under each one a small price to pay for victory.
But We Forgot About...
Let's be generous and assume that every one of the alien city-destroying mother ships was downed. Do you have any idea how large a 15-mile-wide spaceship is? Each one is like a flying city, 1,000-stories high and about 100 blocks wide in every direction. And while New York may not have been designed to have giant spaceships fall on it, we have to imagine the space crafts had been designed with a contingency plan for gravity.
We're not sure how many troops and crew were on board each, but we know each one housed an entire air force worth of those little fighter craft.
Speaking of which, any aliens who happen to be sitting in one of those crafts is probably going to make it. We saw earlier that an alien shot out of the sky was able to survive. And by survive we mean it hot wired a human brain and had a conversation with the fucking President after going through a crash-landing, a cold cock delivered by none other than Will Smith, and being cut in half on an operating table.
Take into account the weaponry the aliens will be able to recover from their downed ships, and we have a District 9 situation on our hands... only we're the ones herded into camps.