Why did the same crowd that welcomed Jesus crucfy Him a few days later?

[Glacies]

The Redemptorist Founder and Doctor of the Church St. Alphonsus Maria de Liguori (1696 - 1 August 1787) explains in his book on the Holy Mass that the Jews lost their respect for Christ after they saw him maltreated by their priests, and concludes that in a parallel way Catholic priets diminish the reverence of the people towards the Holy Mass if they celebrate it without proper devotion. In fact the 1545-1563 Council of Trent teaches (Session 22, Chapter IX) the greatest care should be taken that the Holy Mass is celebrated with all inward purity and outward piety.

St. Alphonsus de Liguori, The Holy Mass:

The heretic who does not believe in
the real presence of Jesus Christ in the holy Sacrifice is
guilty; but more guilty is he who believes in it and
manifests no respect for it. Moreover, the priest who
celebrates Mass with little respect causes those that are
present to lose the esteem and the veneration due to the
majesty of so great a sacrament. The Jewish people
had at first great veneration for Jesus Christ; but when
they saw him despised by the priests, they lost all the
esteem that they had entertained for him. So, also, at
present the people lose the respect that they had for
Mass when they see it treated with so much negligence
and indevotion by priests. As a Mass celebrated devoutly
inspires devotion, so, on the contrary, the irreverence
of the priest diminishes the veneration and even the faith
of those that are present.

The Council of Trent, Session 22, Chapter IX:

it is also sufficiently clear, that all industry and diligence is to be applied to this end, that it be performed with the greatest possible inward cleanness and purity of heart, and outward show of devotion and piety.