Personal trust lists are not really worth paying that much attention to. Unlike ratings, they're backround metrics that affect how the one that sets them in his own profile sees trust ratings.

They only become impactful to the general userbase once they contribute to including/excluding someone in default trust. I wouldn't care that much what the reasons of someone trusting/distrusting others are.
Unless of course they themselves are in DT1 and are largely contributing to preventing others from ranking up. If there's no good reason for such specific actions, it's worth discussing more than hypotheticals.