The problem with this question (beyond the fact that folks leaving Mass don't really want to be nagged with questions, they have places to be!) is that if we changed the question to: "Do you say the Hail Mary," we'd get exactly the opposite result - and praying the Hail Mary to Mary is one way by which people worship Mary. If we changed the question to: "Did you place any candles at Mary's side altar," we would still get a lot of affirmations. That too is an act of worship - an act of religious devotion.
The importance of asking the right Marian question is highlighted in this paragraph:
I asked the women I talked to as part of my research, "Do you think that she's more important than God?" and they say, "Oh, no." But if you say to them, "When you pray, whom do you pray to?" they say, "Guadalupe, Mary." I say, "Why would you go to her with things that you would not go to God with?" "Because she's a woman, she understands."(source)
It is great that the women recognize that Mary is less important than God - it is sad that they think that Mary is more understanding than God - it is sad that when they pray, they pray to Mary. This particular researcher does not seem to have asked the direct question, "Do you worship Mary," but the question is answered indirectly by identifying the object of the women's prayers.
I realize you may still have doubts. Consider the story told at the conclusion of the same article:
I'll tell you this story. I was with a Spanish priest, and he was showing me around the basilica and there was this old man on the side. The priest said, "Hombre, what are you doing here?" And the old man said, I want to pray to the Lady." The priest replied, "Well, I don't see you praying." And the old man admitted, "Oh, Father, I don't know how to pray." So Father said, "OK, here's a prayer book." The old man said, "I don't know how to read," and then the priest starts yelling at him, "Well, what are you doing here?" And the old man said, "You know, it's just enough for me to look in her face."Shouldn't those words, "it's just enough for me to look in her face," help people to see that what is going on here is not the Christian religion but idolatry?
The author of the article, a Roman Catholic, explains in the article how people ask him to pray for them to Mary - so many that he keeps a notebook with their requests. He even suggests that, though he did not pray for it, a serious illness he had may have been cured by making the pilgrimage to the shrine where this particular idol is displayed.
At that point he said:
I was able to surrender, to say to Guadalupe, "You more than anyone know what it is that I need or want. Just give me the strength to be open to that."Is not the blasphemy of that claim transparent?
Now unto him that is able to do exceeding abundantly above all that we ask or think, according to the power that worketh in us, unto him be glory in the church by Christ Jesus throughout all ages, world without end. Amen
And following that up with a similar manifestation of the Christian religion, I shall conclude this article.
Now unto the King eternal, immortal, invisible, the only wise God, be honour and glory for ever and ever. Amen. (1 Timothy 1:17)