Well if you expect trust to be a given you just do away with the politics aspect of the game. You need to make the right decisions and make your nobles happy if you want their trust.
At least that's how it should work, and in my experience it's always worked like that.
But that's a very absolutist way of looking at it—as if "trust" were something you either gave completely, or not at all. And I certainly see that there are people who treat it that way.
But in reality, it can be much more nuanced than that. To take a very simple example, you can choose to trust new players and new characters in your realm, welcoming them rather than instantly suspecting them—but still not giving them access to your most secret counsels. In general, players
should trust their realm-mates, but this
does not preclude a certain amount of politicking, and even spying.
An attitude has arisen in the past several years—and I think it is due, at least in part, to the rise of SMA—that the default position of every noble should be to be out for their own good, and screw everyone else who gets in their way.
Personally, I find that to be an
exhausting way to play the game. I've done it, and done well—Alanna Anaris held the throne of Pian en Luries for
years in an environment that was practically a distillation of that attitude—but I don't think it's what we want for the game. It's not, for most people,
fun. And fun
for most people is what we should be striving for. Not fun that has to be fought for, but fun that's given—and, more importantly, shared.