I said yesterday that I'd contradict myself and dammit, I intend to do so!
I've been in the starting stages of starting a Star Wars RPG campaign with a couple friends for a few weeks. Originally I was just helping with physics homework but you know how nerds are, with one thing leading to another. Early on in this long starting planning phase I ran into a major problem: I'm really bad at creating backstories. Why am I working with another thief to steal from the Empire? Alas, they did not accept my reasoning that I was a pyro who figured he'd steal before burning. Also thrown out was the idea of stealing for shits and giggles and figuring the Empire had some really cool giggles. We've still not quite resolved why my 16 year old character is hanging out with a 30-something year old woman, but hey, who didn't think about that at that age? Which if you're thinking what I'm thinking, that's been just short of explicitly given the no.
Previously I've complained about content being split into a "fun" and "trivial" (exaggerated word choice) track, especially when said content isn't even all that different. It was in the context of ICC hardmodes and how they are the same boss, 90% the same fight, in the same place, but a lot more fun. It seems that good-evil splits in games often follow this route. You fight more or less the same enemies in the same places, just you say meaner things while you do it. Along the way your alignment may cause unexpected problems, such as recently in Stalker: Shadow of Chernobyl where my little tiny shooting someone in the face incident got taken all out of proportion and one of the major faction who show up half of everywhere decide to shoot at me on sight, even if they've never seen me before.
The overall plot is often unchanged, just with the slight twist of "you're the bad guy now, kath hound!"
Does this add any replay value? Maybe. A little bit. I mean, you probably want to play through a second time to see what happens if you backstab everyone you meet, but it's not really a fun or content doubler.
How about rather than pretending to give me a choice, you just give me a good story to play through? Just one. Maybe I'm a good guy, maybe I'm a bad guy, maybe I'm something in the middle. But give me a story to follow, not one to intermittently influence in barely more than cosmetic ways. It feels bad to finish a story a certain way only to later learn from fifteen consecutive hours on tvtropes or wikipedia that my ending wasn't canon and in fact I saved the kitten farm rather than calling in an orbital bombardment. If I can't really be evil, don't give the illusion! It's cruel.
But just to double up the self-contradiction, maybe choice really is ideal and the true problem is that we don't have enough. Maybe the ideal is to give other characters stories to act out while I am the free agent between them all. Maybe I should be able to just fucking stab Kreia with a lightsaber after her first obnoxious lecture about morality when she's planning to ruin everything, which if you're familiar with her plot, wouldn't the destruction hurt everyone, possibly even killing everyone? As much as people say they'd rather die free than live a slave, the particular slavery wasn't all that bad compared to whatever sort of horrible death would result from the 'liberation'.