My major concern is that private revelations seem to take the place of devotion to the public revelation found in the Sacred Scriptures and Holy Tradition in the minds of many poorly catechized Catholics.
Take a step back and
check yourself before you wreck yourself: based upon *what* do you know "the minds" of any kind of Catholics and their devotions? I have a concern p'knight that you seem hot 'n heavy to criticize
Divine Mercy, and its devotees. You've given no evidence that you know what Divine Mercy Sunday [or any devotion] is, yet you're freely spouting a critical opinion. It is not difficult to make a connection spiritually between the celebration of the Second Sunday of Easter and Divine Mercy; by it one can appreciate more intensely, and grow closer to, The Word.