If you are uncivilized and behave like barbarian being self-indulgent, unproductive, untrue, and impolite, but live in first-world civilization comfortably, then indeed, you have an unearned virtue that justifies "white guilt".
Funny enough though, there is, or there should be discovered as much of this same "white guilt" among black, Hispanic, aboriginal people, or perhaps more than among white-skinned people.
High quality of character is possible under black skin, Martin Luther King was correct.
Yet poor quality of character is also possible, and Martin Luther King also proves it with his own life.
Bad character distributed in an uneven way but is possible under any suit, dress, uniform, and skin color.
So the misnomer of a White Guilt must be shared proportionally.
I would call it properly "First World guilt". Not all the First World inhabitants deserve all the good lives they got, and first-world privilege justifies first-world guilt.
(I would sidetrack a little, and say that indeed, the good life is not equal to a pleasant life, and first world has an abundance of pleasures for nearly every taste, while good lives are not in abundant supply and still in high demand, but this matter requires separate mini-essay.
Also, First-World guilt is particularly strong among high prestige professionals, who are predominantly white and highly educated, but this is another matter for another discussion.)
Used in a good way, this First World guilt should be a vehicle for self-improvement and individual charity. In a bad way, it is a fuel for civil unrest and self-destructing policies.