@heretic_hanar
Simply put, when playing as a Renegade, in particular a "Humans-First" hard arse Do what it takes to forward Humanity rise to power, and not "jackass psychotic ahole Shepard, I could essentially play in a morality-vacuum and even complete the game with the original endings (pre or post EC) and it didn't bother me.
Its when I played as a Paragon that the end felt railroading me towards a character that wasn't in character with what I played.
Example. Renegade kills Wrex because its an alien and in Shepard's own words, an animal. His mental state is that *all* Aliens are animals to a degree, and yes including the Asari. They may look human-like, but *they aren't human*. And thus any and all aliens are assets to be used, abused and discarded when no longer needed or prove more trouble than they are worth.
With this in mind, killing the Rachni, the Krogans, shooting Mordin in the back, destroying the Geth, EDI and maybe even the Quarians are all just business. Its war, you use your assets in war and use them for the betterment of the Human race.
The fact that I *can* play as such but not have the same satisfactory end for playing as a Paragon (Paragade really, as *pure* paragon is as ridiculous as *pure* renegade) , and the game (ME3) actually encourages you to go on the Renegade path, makes the whole "morality" paths pointless.
Remember, this is a *game* not sim-life drama where a message of "you can't win without compromising yourself" is shoved down my throat.