Who was most responsible for the problems that Jamestown settlers faced: the company directors in London, or the leaders in Virginia?

The main responsibility for the problems of the Jamestown
settlement had to do with the way the colony was imagined, not with the way that it was
run once it was set up in Virginia.  Therefore, the fault is more with the company
directors.

The company directors assumed that the settlers
would be able to find a labor force among the natives.  They expected to make money by
trading with those natives, using them as workers to produce goods, and by extracting
precious metals from the earth.  None of these things turned out to be possible.  The
colony suffered mainly because of this.  The strong leadership of John Smith (though he
had flaws) was what kept the settlement together until a different economic model could
be devised.