It was nice to see the Pope note that May is the Marian month. In many parishes around the country, there were Mary crownings and Marian hymns, a reflection of popular devotion that is not reflected in the readings or the Graduale at Mass, at least not insofar as I can see. So this makes the Marian aspect of the day a "popular devotion."
Yet a certain generation of priests seems to have an issue with popular devotions. They believe that it is better to suppress them in the name of liturgical scrupulosity - probably something they picked up in seminary training. There might be some basis for this; I really don't know. I can imagine that if I were a pastor of a parish that has some group that gets carried away with a fixation on a certain apparition, it might become tiring.
And yet: it is not the case that every Sunday can have only one "theme" such that if we recognize Mary on the first Sunday of May we cannot also learn from the Gospel readings and Graduale texts. A liturgy that is 2000 years old is going to be rather complex, with many layers of meaning. Popular devotions can surely be among them.
In any case, so long as there is no heresy at work (truth gone mad) is there any real point in clamping down on popular devotions? Does it really make us more devout to keep our brains attached to the readings and only the readings? Is there a long history of some sort of competition between the formal liturgical year and the devotions that emerge from among the people?