The key to seeing why there should be a Eucharistic worship distinct from the Mass is that the Eucharist is Jesus Christ. No less than His contemporaries in Palestine adored and implored Him for the favors they needed, so we should praise, thank Him, and implore Him for what we need.
Pope Pius XIILet no Christian therefore, whether philosopher or theologian, embrace eagerly and lightly whatever novelty happens to be thought up from day to day, but rather let him weigh it with painstaking care and a balanced judgment, lest he lose or corrupt the truth he already has, with grave danger and damage to his faith.
Pope Pius XIIThe more pure and chaste is a soul, the more it hungers for this Bread [Jesus in the Eucharist], from which it derives strength to resist all temptations to sins of impurity, and by which it is more intimately united with the Divine Spouse; 'He who eats My Flesh and drinks My Blood, abides in Me and I in him'
Pope Pius XII