Our document wraps up its overview of history. It wasn’t all bad in the times leading up to the turn of the 18th/19th century. Sacra Tridentina lauds the testimony of some who thought frequent Communion would bear fruit:
On the other hand, there were not wanting men endowed with learning and piety who offered an easier approach to this practice, so salutary and so pleasing to God. They taught, with the authority of the Fathers, that there is no precept of the Church which prescribes more perfect dispositions in the case of daily than of weekly or monthly Communion; while the fruits of daily Communion will be far more abundant than those of Communion received weekly or monthly.
Which brings us to 1905, and the situation is presented plainly, acknowledging that some heat and bile were still expended on this matter.
In our own day the controversy has been continued with increased warmth, and not without bitterness, so that the minds of confessors and the consciences of the faithful have been disturbed, to the no small detriment of Christian piety and fervor. Certain distinguished men, themselves pastors of souls, have as a result of this, urgently begged His Holiness, Pope Pius X, to deign to settle, by his supreme authority, the question concerning the dispositions required to receive the Eucharist daily; so that this practice, so salutary and so pleasing to God, not only might suffer no decrease among the faithful, but rather that it increase and everywhere be promoted, especially in these days when religion and the Catholic faith are attacked on all sides, and the true love of God and piety are so frequently lacking. His Holiness, being most earnestly desirous, out of his solicitude and zeal, that the faithful should be invited to the sacred banquet as often as possible, even daily, and should benefit by its most abundant fruits, committed the aforesaid question to this Sacred Congregation, to be studied and decided definitely (definiendam).
O yes: the church felt persecution even before modern ideologies flowered. The desire to restore a practice of frequent Communion is justified in part by the hope that the faith witness of the laity be firmed and strengthened in difficult times. A rather optimistic view, don’t you think?
This matter was studied in the months and certainly years leading up to this document. In the next post or two, we’ll wrap up by looking at the particular prescriptions Pope Pius X placed on the Church.
Catholic Sensibility 
“A rather optimistic view, don’t you think?”
Actually, more prescient, especially one considers the awful if shortened 20th century (1914-1989); the people needed fortification not only for attacks on religion generally or the Catholic faith itself (though those did indeed occur on a massive scale in some regions, such as Mexico, Spain, and much of Eurasia), but the more general state-sponsored terrorism against human dignity.