Impenetrable deserts aren't known for their abundance of fresh water. Just having resources available isn't everything either, you have to know how to extract t

Impenetrable deserts aren't known for their abundance of fresh water. Just having resources available isn't everything either, you have to know how to extract those resources, this is a massive barrier to a primitive (excuse the term) culture landing on an alien continent, separated for millions of years. Living off the ocean is also incredibly dangerous.