Picking a tone is a great idea. Also, there's more to that system, not just a tone. There are your classic dialogue choices, but only when there's a choice to make... Tone = personal reaction, which is imo much more suitable in case of cinematic, movie-like cutscenes.
You don't need stats or skills to have an interesting dialogue system, keep that crap in classic CRPGs. Is that your argument? Really? Conversation mechanics are bad, because there are no stats/skill checks? That's just a stupid non-sequitur that might you win some free blowjobs brofists from edgy codexers but hardly a relevant critique. There are aditional mechanics to that system actually, which you can find on wiki and which passed unnoticed by a vast number of players. Those are great and the whole dialogue system in DA2 is one of the first attempt to make a systematic conversation mechanics that are divided into categories. I hate that there's not a coherent approach to dialogues in IE/Arcanum/Fallout games, btw. PLanescape Torment had great writing, but it would be much better with systematic dialogue design.
Regarding ME2... Fall for tripe? I don't know isif stupidity is a bliss, but ignorance and dogmatism surely are...