[stefco_]

Absolutely, those are very good points, though not all of those problems are best solved by manned missions (e.g. exploration can be more efficiently performed if life-support systems are unnecessary). Increasing human survival odds definitely does require manned missions.

But, from a cultural enrichment/learning/individual experience perspective (which I, perhaps incorrectly, assumed the parent comment was referring to) a sufficiently accurate simulation with appropriate man/machine interfaces is a far more efficient solution than manned spaceflight over interstellar distances (provided people can get over their discomfort with the ontology of simulacra).