Whichever function one uses to judge a person's type according to external standards, the Judger sees only motives, which is Ego. The dominant function supports the Ego. The reason we act on the Ego is for the Ego's own satisfaction. Judger's are motivated by their own Egos more than Perceivers.
It never ceases to irritate me when a Judger claims that I acted according to such and such motive. And whenever you find someone habitually starting sentences with "That's because you...", you can be assured this person is a Judger, whether Ji or Je doesn't matter.
"Of course you did, you wanted to win." "Of course you think that way, you're a racist."
Imputing motives to others is very easy and is often correct; not always. But I've never met a Judger who didn't think they were always correct about it. Of course, they think they're really smart.
We Perceivers obviously think we're above all that Ego motivation. But that's because we're Perceivers.