A lot of folks seem to be focused on the good vs evil thing, I personally prefer to go with the idea of altruism vs ruthlessness and I'm not particularly worried if a goal is the same for multiple paths in a game, as long as the play experience along the way is different and you can change the outcome by your choices. To give an example of what I mean, take the following scenario (it's going to be terribly simple and involve kittens, don't mind that or read too much into it).
Basic scenario is you have a bunch of warring/bickering states and a big bad over yonder who is going to come along and drown all your kittens unless you stop them (not familiar at all right?). You need to somehow put an end to the local bushfires and defeat the big bad thus preserving your kittens for posterity. How you go about doing that and the outcome of the game are where the story is. Three basic paths:
Altruistic noble hero - you're going to use diplomacy and personal charimsa to unite like-minded fellows in a grand alliance to defeat the big bad and have a golden age of enlightenment and kittens for all.
Ruthless bastard - you're going to use whatever means necessary to force everyone to follow you, whether its torture, assassination, intimidation or brute force to forge an empire that can take on the big bad, resulting in you plonking your butt firmly on a throne of blood and keeping all the kittens for yourself in a thousand year empire ruled by an iron fist.
Opportunistic player - you'll take the middle path, using what seems appropriate at the time and probably end up with a loose association facing the big bad, and if you win you'll probably end up splintering into warring factions again as soon as its time to decide who gets the kittens.
End goal is exactly the same in each path (defeat big bad), but how you go about it and the resulting outcome will be very different. You might even have the option to throw in the towel and be the big bads viceroy and snaggle a kitten or two for yourself while betraying everyone else to a horrible kittenless existence.
tl:dr - As long as the choices you make affect the experience along the way and the overall outcome, I guess I'm fine with it even if you do end up with points where the paths converge occasionally.