Summoners have been proven to have a better overall dps than Red mages. I believe Red mage easier than SMN to be optimized which is why we have high dmg red mages overall. And the thing is Red mage don't waste time to change their habits, they just get used to that new gameplay, instead of looking at what they've lost etc.
Don't look at the past, and focus on what you can do, and you'll see SMN have better dps than Red mages (at least lvl 70).