If you believe in the objective truth of the quoted source, then that makes the claim that humans are valuable about as robust as any claim can be.

If you do not believe in the objective truth of the quoted source, you must still reckon with the fact that this is the (start of) the punchline of the opening narrative of the foundational text of the world's largest religion or religion family. (The punchline continues with the judgment that the universe, being merely good before humanity, is now very good with humanity.) That is to say, this is an incredibly widely and deeply held value by a vast number of people over millenia, not to mention the many others whose religions may contain analogous claims.

Remember, the statement "X is valuable" is always shorthand for "X is valuable to Y". In this case, at absolute worst we mean "humans are valuable to humans," if not also "humans are valuable to God".

It is a forceful argument when carried through.