If i have a motivation of something, i can abandon it if my companions/co worker/platoon/whatever betray me. I don't want to take part in any of the bullshit they are going through. If they succeed in whatever they are doing then congratulation, but if they don't then they got what they deserve.
It's simple
Well, good for you.
As about why Alistair give the junior to lead, it is because the game require you to be a junior, not his fault in that. Blame the writer. It is a point where he don't have any defense of in story wise. You must lead because you are the player.
I'm sorry, are you serious? Why would I blame the writer when it comes to character development? It's they who designed Alistair, he didn't just pop out of thin air. If the writers wanted to portray him as an indecisive person, someone who's more comfortable following orders than commanding, then that's exactly how Alistair was supposed to be. Whether the writer did a good job or not portraying him, I'm not competent enough to comment on that.
It is true that from a gameplay perspective, the player is going to lead the party, but it wouldn't really have taken that much of an effort to make Alistair a bit more involved in the decision making process if the writers really wanted to. Your logic says that Alistair followed the warden because the warden is the PC, in the same way it says that Alistair put up with the warden's decisions only because he was the PC. Even Wynne and Leli could possible die opposing the warden, but we couldn't have that for Ali because he was an important piece of the political puzzle. You see, no credit to Alistair's personality. He was only considerate because the game demanded it, lest the warden guts him sometime. Is that what you are saying?
About Riordan, you just meet him, you don't even know who he is, maybe he's a spy, maybe he's a bad man, maybe this and that, maybe he's working with Loghain, maybe he's bribed...the point is, you know Alistair longer than you know Riordan. At that time, at that place, at that moment Riordan is just a guy who suddenly show up and try to sheanigan all your works...so no, I DON"T AGREE with him at all
Alistair recognizes Riordan from his joining. Riordan is a senior grey warden. In armies the common soldier generally knows his fellow comrade in arms better than his commanding officer; doesn't stop him from following orders, does it? A senior officer can take command of a company that has lost it's commanding officer, provided none of the survivors are of higher rank than him. Well, that is how it works in real life. It might be different in the DA universe, but I highly doubt it, seeing how the First Warden sends Mistress Woolsey to take control of the treasury in Amaranthine, and no one is given the opportunity to oppose it. So, at least some sort of chain of command does exist.
You play as a guy/girl who just being recruited, know nothing about being a Grey Warden but want to talk about how a Grey Warden should be? No, my judgement there is as who ever i play, not as Grey warden at all....either as Cousland, Mahariel, or whatever race i play, not as Grey Warden at all.
Despite everyone call me "Warden", i never consider being a Grey Warden at all...anyone could do what the Warden do, things that make it difference is the ability to kill the Archdemon
You can speak for yourself and your wardens. That might not be the way my warden or somebody else's warden think. It's true that the PC had been a warden for a very short time, but during that short duration s/he'll form his/her own opinion about what a grey warden would or wouldn't do, which in your case I presume, if I may, is more about honor and glory. This may not be true about other players. In those cases, the warden might have accepted the ideology that any means is permitted for the greater good and that Honor, Friendship, Love is secondary. Worth noting that Wynne seems to agree to this particular view, while Sten I guess is someone who advocates honor, but at the same time he also has a strong sense of duty and ethics.
Since this has dragged on too long, I'd like to make myself clear if I hadn't already. In my first post regarding Alistair's leaving, I wasn't saying Alistair's refusal to stand alongside Loghain as a comrade is wrong. I was simply questioning his abandoning the wardens when so many lives were at stake. It was a bit too selfish for my taste. If Alistair didn't want to play buddies with the warden from there on, that is well and good, but he could have at least waited till the end of the battle. Afterwards he may have left Ferelden and joined some other nation's wardens or anything of that sort. No matter what are the reasons for his outburst, breaking the warden's oath is not worthy of a grey warden. His heart is clearly at the right place, he's kind, but he's surely not much fit to be a warden; one day or the other, he's gonna break down, if not in the landsmeet. That's the only thing I was saying. For all I know, Alistair probably has the most clean record of all the lunatics in the warden's camp, including the warden. Most of them are killers, apostates, assassins, minstrels, bard, bird killer and what have you. Still doesn't mean his breaking the warden's oath will be overlooked.