Since the goods in the cache constitute a source of goods for much less effort than 'in-house' production, I can't see any colony ignoring the cache...
Icosahedron,
First, there are goods and then there are goods.
While the crusoe cache would have spare parts for starships(1), vehicles, and other equipment, the long term rations part of the equation was something else entirely.
There would be water purification equipment and enough already purified water to hopefully allow not to die of thirst before you set up the purifier.
Food stocks were just as limited. You had enough CHON(2) to keep you going until you could hunt, fish, forage, and grow crops. There would be hunting and fishing supplies complete with instructions about which few species the cache builders had determined were fit for consumption. There would be foraging guides too, eat this part of this plant and avoid that part of that plant. Seed stocks were also limited to those very few Earth and Earth-descended crops the cache builders knew would grow on Idiocracy-II.
The M.O. for using the cache was to stay long to either repair your ship or build the s/c while keeping yourself alive. You were also supposed to replenish the stocks you used, making more CHON, storing seeds, storing water, leaving behind raw and finished materials, and so forth. (While you were supposed to do this and official groups were supposed to check on the caches every decade or so, it would be wise not to assume either happened.)
Second, it was also a question of numbers.
The crusoe cache was designed to keep ~100 people alive until they could hunt, forage, and farm enough to stay alive indefinitely. A colony mission would have perhaps two or three orders of magnitude more people aboard. That number would blow through the crusoe cache food stocks in no time.
The cache's equipment, parts, and materials stocks were too limited in scope for a colony's needs. The cache's technical aspects was designed so that you could build the two rescue vessels I mentioned above. A colony wouldn't need those ships. The cache's material processing equipment; i.e. mini-refineries, mills, etc., were also limited in capacity and narrowly focused. Again, just big enough and designed specifically for building that scout/courier and shuttle.
The cache and it's contents simply weren't big enough and flexible enough for a 10 to 100 thousand person colony to either use or plan on using. Certain portions may have been "looted", but the rest really was of no use.
... and growing around/over it unless the colony was so small that it couldn't use up the entire cache before the collapse came.
The colony wouldn't be using the cache to begin with and the collapse would come long after the colony's founding. The cache would first be ignored, then forgotten. The colony's main city would eventually grow around it. Buildings would abut or cover the mostly underground bunkers. It would always be too much trouble to dig up the entire cache and remove it. With a mostly empty planet, land prices in the "First Landing" city wouldn't get high enough to be worth the effort.
By the time the colony devolved into Idiocracy-II, the cache would be entirely hidden and forgotten.
Regards,
Bill
1 - I figured that sufficiently competent castaways could build a very basic grav shuttle and a very basic scout/courier from the stocked parts. The shuttle to build the scout/courier in orbit and the s/c then to go for help.
2 - A direct rip-oof from Pohl's
Hee-Chee novels. It stands for the stuff that makes it up: carbon, hydrogen, oxygen, and nitrogen. While it will keep you alive and healthy, it's essentially a bland mush no one will eat if there are any other choices.
