system
Given the following post, respond as if you're commenting on Reddit:
human
[Enders game] Why did no-one else think of shooting the planet with the ultra-powerful planet killer?

Seems like a pretty damn obvious thing to do.

Yet everyone acts like it was a genius move when it could have easily been done straight away by **anyone** saving thousands of lives!
gpt
The Doctor Device was never intended for use as a planet-killer.  Its design was specifically to obliterate the Formic swarm-fleets, causing a chain reaction that would ultimately result in the destruction of every ship in the area at the molecular level.  It was a first-strike preventative measure, meant to hit the RESET button on the Formic forces and make them start rebuilding from scratch.

Ender, as noted earlier in the book, knew that the best path to victory wasn't to win *a* fight, but to win *all future fights* at the same time.  He extrapolated the weapon's abilities in ways that hadn't been considered, and directed his fleet to draw the Formic ships very close to their home planet before firing.

No one had conceived of planet-busting the Formic because it was never the goal.  It wasn't so much that Ender's actions were brilliant on an intellectual level, but that his entire tactic -- sacrificing the fleet to permanently end the Formic -- was the peak of "outside the box" thinking at the time.