Can't it be because they are proud of accomplishing something difficult? The harder the challenge, the greater the pride. Also, you're looking for a specific

Can't it be because they are proud of accomplishing something difficult? The harder the challenge, the greater the pride. Also, you're looking for a specific answer to a very abstract question. You can't ask why something is highly-valued without specifying by whom. Is there a particular instance of this behavior that you are looking to explain? Otherwise it could just be confirmation bias.