It is short sighted BS, but that is what being a GC is all about, cutting a corner so you will be low, then hoping your subs don't catch on until its too late and they have to foot the bill.
Realistically what would a job site look like if every sub had a dumpster on site? What would the the bids to the GC be if every sub included the cost of a roll off dumpster? Pretty soon the GCs would figure out they could save a tone of money by just including one in their general overhead.
