Fair to say, much damage has been done to the Church by people innovating from false or vague appeals to antiquity or catholicity; as many more "catholic" minded Anglicans would rather accept their church being a continuity of the "Celtic Church" than a product of the Protestant Reformation

How did "Celtic spirituality" even come about in the first place?

You see "whiny", I see caring; because beyond the stereotypical "trivial" sins you may be thinking of, there are real harmful and destructive things we ought to turn from and if you really used and examined the BCP (where this prayer came from), you would know that...

But, even if it were bad, there's now an overcorrection in modern liturgies where people are now downplaying that aspect even though there is a judgement. There should be a balance between because while God is love, that love is extended through mercy as well, and God does desire repentance

Really works well as a self examination of conscience

Did this portion privately in addition to the 1928 Penitential Service and it was deeply moving, and perhaps was a better contexualising of Lent than the ashing