Movie plot question

[Syrin]

Why didn't they just nuke every last corner of the bug planet instead of getting troops killed on the ground?

[rah]

You can't setup equipment for mining on an irradiated planet surface. Even if you send drones, radiation ends up messing with electronics.

[100% Recycled Awesome]

Because the movie was satirical.

In an actual invasion, they don't even need nukes. Space supremacy would allow a fleet in orbit to harvest asteroids and just mass driver them, Centauri Empire on Narn style, or more recently, Riker on Changelings. Asteroids are cheap. Nukes are expensive. Just accelerate the ship carrying the asteroid, launch the asteroid, stop the ship from hundreds of thousands of miles away. The plasma bugs can't reach them there.