Our Lady Of Lourdes

Today the Church celebrates the appearance of Mary to Bernadette Soubirous in the 19th century. The fruit of this appearance was a massive renewal among the faithful that spread worldwide and continues to this day.
When I was a non-Catholic Christian, I assumed these must have been satanic in origin or fraudulent because I refused to believe that God would or could allow these things. Yet, at the same time, I gave creedence to those in my fellowship who claimed to have dreams, visions and prophetic utterances directly from God*. (including those who claimed that God told them when the Lord would return)
Why did I find it so easy to accept these "apparitions" or visions that individuals had as valid, and yet completely refuse to accept apparitions of Mary that often changed the course of history in a positive way? (ie Our Lady of Guadaulpe which ended infant sacrifice among the Indians of Mexico and 9 million conversions to Christianity from paganism)
These Church- approved apparitions of Mary have always had the effect of increasing piety and devotion to Christ, since the nature of the apparitions was to focus on Jesus and
"Do whatever He tells you to do." (John 2:5)

*I must admit, the first time I heard a prophecy in our little prayer group, the prophet started by saying "I am the Lord Your God..." I was immediately "creeped out" and stuck my fingers in my ears so I wouldn't hear it because I thought it blasphemous. I felt it was terribly wrong and had no sense of peace about these prophecies.
I think that was the Lord telling me then: "Get thee to back to the Catholic Church"
Of course the gift of prophecy exists in the Catholic Church where all the gifts continue to reside, but they must be "vetted" and in the appropriate setting, and not for the self-interests of the one manifesting the gift.