I am probably speaking out of turn since I haven't finished the game, but so far I find both Angeal and Genesis do the jobs they are meant to do in the story just fine, given the constraints of the medium. I would also respectfully venture to suggest that fighting for Shinra is not necessarily a meaningless and shameful existence. Sure, they are kind of evil, but AVALANCHE is also kind of evil, in the sense that for both groups the end justifies the means and the nameless mass of humanity is disposable in the quest for the greater good. Shinra started as a weapons company and now it makes electricity, which suggests that for many people on the planet an era of warfare has been succeeded by an era of comparative peace, admittedly peace enforced on the point of Shinra's sword. But nobody other than AVALANCHE and some people in Wutai really care. It's not that things are great now that Shinra's in charge; far from it. But maybe things were worse before. The only real problem is that using mako drains the Lifestream, and Shinra's working on that. If Shinra could really find the promised land - yes, Rufus and his dad would be even richer (does money actually matter to them any more?) but everybody would be better off.
Yours faithfully
The Shinra PR Department