For a long time, the Incubator accumulated a lot of resources.
It did not indiscriminately devour every piece of trash it came across. In fact, the longer it existed, the more the Voribug Organic Battle Moon grew picky about the salvage it devoured.
The Goliath Hive clearly wanted to feed the best quality resources to the unknown entity gestating inside its core.
Throwing low-quality materials in the mix would force the Incubator to sort out the good from the bad and waste a lot of time and energy in the process.
It was due to the very deliberate discernment of the organic megaconstruct that the opposing humans so easily managed to deduce the Goliath Hive's intentions.
Even if the Ascended Giants did not complete their costly reconnaissance mission, the Rubarthans would have put the clues together eventually.
However, it was exactly because of the advance warning given by the giants that the defenders had time to figure out a number of countermeasures.
