They are quite attractive. Every solar panel at minimum means less pollution and less fossil fuels. Just like putting insulation around pipes to prevent temperature loss, although as in your diagram solar is only 1 point behind natural gas. Solar provides the incentive of greater deployment and no subsequent fuel in comparison.
The EROI is apparent with solar and has been since the 80's, the difference now being that the cost has gotten so low that it should be deployed everywhere possible! It is the wise choice to utilize the abundant energy that takes little to implement compared to the extraction process, threat from spills, and pollution given forth in the use of fossil fuels.
It is more than diversity, it is protecting quality of life.