JS: the most Blessed Sacrament is indeed Holy. Thus those in sin may receive it but they do so at their own risk. Who knows, by doing so they might also be convicted! That said, the L-rd G-d Almighty does not see as we see, so we should always be careful and forgive their trespasses as we hope to have our's forgiven as well.
Yet who really is holy? The Messiah was holy and they crucified Him, but the rest of us fall short of His Glory. Thus we are called to be humble and contrite when receiving, not because we be perfect, but by being humble and non judgmental, He will bless us with Himself, cover even the sins we ourselves do not see, and heal our broken hearts.
So none of us is perfect, but hopefully we are all working toward perfection (in love).