But why? There is nothing preventing him from giving up the search and leading normal life. He keeps punishing himself even though he can stop at any moment.

He think if he keeps doubling down all this can be set right.

Possibly, but it seems like a dangerous gamble. He could spend millions in resources and there very well (or even very likely) will be nothing recovered. Also, what are the odds that the magnetic media could survive yearly weathering like this for ~ a decade (not to mention pressure of junk and bulldozers up top)?