One of the most crippling movie
cliches of the
science fiction genre, as evidenced by films such as
Titan A.E.,
Star Wars,
Return of the Jedi,
The Last Starfighter,
Independence Day, and many others.
As is probably obvious from the name, it involves placing all the important personnel, hardware, control mechanisms, etc. on one "invulnerable" platform. The Death Star is probably the most popular example of this folly which only the most incompetent of would-be galactic conquerors would engage in.
Even worse than the original Death Star was the repeat lunacy of RotJ, in which the entire starfleet was held back from attacking the rebels just so the emperor could have a good laugh.
Titan A.E. is the most recent perpetrator of this stupid cliche, this time going so far as to have an entire race bundled up in one massive space cruiser. Put this one together with Indpendence Day and we should have no problems giving any hostile alien civilizations a good drubbing.