Seed of Corruption vs Rain of Fire

I'm a Destruction Warlock. I have been a Destruction Warlock for a very very long time. I thoroughly enjoy the mechanics of the Warlock class and the Destruction tree play style. When Affliction was the obviously dominant spec in early Wrath, I STILL only played Destruction and did without some raid invites because I don't particularly enjoy the Affliction play style. C'est la vie.

Therefore, I am confused about why, when I want to maximize AoE DPS, I am forced to use the obviously better Seed of Corruption, what seems to be an obvious Affliction-esque AoE spell.

This isn't a small difference. Rain of Fire hits for 1500-1800 per enemy and crits for around 3500-3800. Seed of Corruption, on the other hand, hits for 3000-3500 and crits for over 4500 most of the time. That's INSANE.

Let's ignore for a second that it's more annoying to use and focus on why a class spec that is generally focused on incinerating everything in its path is planting shadowy explosives in its enemies. I would much rather use Rain of Fire. Is it possible to have Destro talents that enhance Rain of Fire? For balance sake, let's say we "nerf" Seed of Corruption to bring it more in line with the damage of RoF. And then you have specific Affliction and Destro talents that enhance the damage of SoC and RoF respectively?

Is this possible? Right now I'm forced to use an annoying-to-cast spell that obviously does the most DPS or I can use the easier-to-cast spell that obviously does much less DPS. I don't like that choice. Or maybe I'm just doing it wrong? I dunno...

Hopefully I don't get blasted by the community for this. I'm not complaining about my AoE DPS, I just want to get the same DPS from a spell that fits my spec and preferred play style.

Thanks!