Why fight it? Not just because it's patented. The bigger fear is that because it's patented, no one in the US will be able (willing?) to implement it, while folks in other countries with lax enforcement of IP laws (read: China) will. Since mining is a competitive race, a 20% boost should ensure only patent infringers will ever mine blocks.
[1] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2016...