Of course - there are a great many factors behind Europe being the ones to discover the Americas, and not vice-versa. But, importantly, many other Old World regions had the same access to material goods and technology that Europe did - China in particular - but did not end up discovering (or exploiting) the Americas.

The point in rejecting environmental determinism is not the rejection of environmental factors, but the rejection of determinism - history is a vast field, and even small changes can arrest entire civilizations.