"From what I understand, this bacteria does not easily survive on non-biological surfaces. Maybe I'm wrong, but this could be the reason it was not found on surfaces in homes. Maybe someone more of an expert could shed some light? "
Bacillus is a spore former. The spores are quite content to wait around to do their dirty business. It's common to culture strains of Bacillus from soil samples. Spores can remain viable for years in soil or on wool, fur, etc. Sorry.