No, we should only grant obvious patents! They expire the 3rd Sunday after the second full moon. Also the application should cost 1 billion dollars and must be written is Sanskrit.

More seriously, rather than trying to only throw obvious ones out I would suggest applicants submit a bounty on each patent to be paid out when prior art is discovered. Or returned after 5 years. The patent office can then charge a small fee to compare prior art to a patent or patent application and it becomes expensive and pointless to submit most dumb patents without costing the taxpayers anything.

They are obvious because someone (the patent holder) MADE them obvious.