Why did the Company...

[Valtiel]

Maybe weyland-yutani did find the sulaco. but something happened on it leading to their bankruptcy (sp)  trying it to keep it covered up.

Or people strated to aks questions where is everybody from Hadley's Hope?

I thought everyone from hadleys hope where coconed or died in the explosion 

Yes everyone but Newt. But im sure these people would have had families back on Earth. And im sure that these families would have been told that the people on Hadley's Hope all died from a meltdown of the atmospheric reactor. Therefore cleaning their hands of the situation