History is full of people who think like you.

From Columbus's expedition of 1492 (which was derided and rejected by his native Portugal as an impossible dream), to man's conquest of space (which was also derided as pure fantasy by those who warned that the vacuum of space would be instantly fatal and the technology would never be invented to conquer it), to the personal computing revolution, history has been full of naysayers who are always ready to tell you why it can't be done.

Fortunately, history tends to relegate people like that to the sidelines.