I'll go one further. 'Just' is never appropriate (except in irony, such as Mr. Bray's article), in my opinion. It signifies some combination of frustration, an

I'll go one further. 'Just' is never appropriate (except in irony, such as Mr. Bray's article), in my opinion. It signifies some combination of frustration, an opinion of the speaker's mental superiority, and an opinion of the listener's mental inferiority. For these reasons it also often causes listeners to focus on the speaker's opinion or the listener's underlying emotional response, rather than the solution or message you are trying to convey.