The Mass Effect series is supposed to revolve around a dichotomy between being a “Paragon” – doing things by the book, following the rules and trying to be nice to everyone, and being a “Renegade” – doing things efficiently, breaking rules which get in your way, and getting the job done.
This breaks down through play though, because in almost every single case it is at least as efficient to do things the nice way, sometimes in ridiculous ways that undermine characters and weaken the player’s sense of responsibility. One example is the choice about whether to spare or kill the Rachni queen in ME1. It is made very clear that this is a species that will devour and destroy other species if left unchecked. If the ME games stuck to their guns then the “Paragon” choice of letting the Rachni queen free to grow her species again should lead to her creating an expansive force which wreaks havoc in part of the galaxy, possibly tying up a large part of the Alliance. Instead what happens is the opposite – the Rachni queen becomes an ally and there are no negative consequences. If you kill the Rachni queen – of a species that is genetically suited for galactic conquest – then all that happens is a few people are annoyed with you.
Time and again, if the player does the nice but on the face of it stupid thing they are rewarded. This doesn’t just encourage the player to operate as an idealistic fool, but makes everyone who is a pessimist about niceness in the frontier situation of the Mass Effect games into a fool too. The entire premise of the Mass Effect story, one that is drummed in time and again by the characters with experience throughout Mass Effect 1, is that space is a dick and you’ve got to be a dick to take on space. But it turns out that the best approach to galactic catastrophe is essentially to behave like Peter Molyneux. That is why the morality of Mass Effect is lame.