Imputed righteousness is a term invented by Luther...also called "alien righteousness." It maintains that taking on Jesus as your saviour HIDES your true self from God. It steals righteousness from God in order to make it one's own.
Basically it is to be able to
hide behind Jesus. So then rather than Jesus reconciling us with a loving God, Luther's idea was to hide people from an angry God. Sort of like when Adam and Even hid themselves in the garden...but this time it's behind Jesus. So then when God looks at us He can't see us...He sees Jesus instead who is covering us up.
Of course this is so false that men will believe it.
Why?
Because men hate the truth. A chance to coverup the truth will always be popular.
The truth is that we enter into Christ to be empowered to walk as He walked...in complete exposure and intimacy with God. The cleansing is real...not just a coverup.
Luther likened justification to a dunghill covered with a fresh blanket of snow. But he never got around to answer why his theories stank so much.