I browsed the website and the examples. I think he has a good point about concerns with the practice of Marian devotions. I think his quote of de Montfort, though used by de Montfort as a sort of criticism of those who think Marian devotion goes too far, reflects accurately the concern of those who hold it:
"The Scrupulous devotees are those who fear to dishonour the Son by honouring the Mother, to abase the one in elevating the other. They are unwilling that we should speak so often of our Lady, and address ourselves so frequently to her. These are the favourite sentences constantly in their mouths: ‘To what end are so many chaplets, so many confraternities, and so many external devotions to the Blessed Virgin? There is much of ignorance in all this. It makes a mummery of our religion. Speak to us of those who are devout to Jesus Christ. We must have recourse to Jesus Christ; He is our only Mediator. We must preach Jesus Christ; this is the solid devotion.’"
I thought the fervency towards Marian devotion was a more recent phenomenon, but I guess it has been around a while.
And please understand, I am not denouncing Marian devotion, but mentioning the concern (which is reflected in the linked website) over how it is sometimes practiced, where it crosses the line from devotion to something more.
Pax