It's always going to be a compromise. As cap and gown says, the ME1 version - three different options, all of which have Shep say the same thing? Not a good dialogue system. I'd argue ME3's system is much better than that, where Shepard always has at least two different things to say, and even some of the auto-dialogue is based on what the game has deduced of your Shepard's character.
However, I do agree that more dialogue options would be a good thing. But more work put into that would be more work taken away from other aspects of ME-Next... etc, etc, etc. Hence, a compromise. Personally, I'd like Bioware to give us a knowledge based reply system - for example, an Engineer could get extra dialogue about an engine failure, an Infiltrator could make Tactical comments for an assault, that sort of thing. The Charm/Intimidate system also needs an overhaul, and we could do with a bit less auto-dialogue - but I don't want Bioware to put so much work into completely overhauling the entire dialogue system such that the actual plot or gameplay structure suffers.
EDIT - on the topic of Charm/Intimidate: a small change which I think would help with both role-playing and the problem of "select colour to win" that the current system suffers from:
The possibility of failure. Maybe have it so that the coloured options are never greyed out, but that they'll only actually work out in your favour if you've got enough Charm/Intimidate points. So you have the choice - do I risk trying to intimidate this person, or should I pick one of the standard dialogue options? Afterall, if you try intimidating a gang-leader and it doesn't work, there's a decent chance that you've just put your foot in it.