Because knowledge of the mysteries of the Kingdom of heaven has been granted to you, but to them it has not been granted.
I am coming to you in a dense cloud,
so that when the people hear me speaking with you,
they may always have faith in you also.
One of the things that gripes me most is when someone who rejects the scriptures wholeheartedly tries to tell me what they mean.
I don't care if that's your average person-on-the-street who says "let me tell you what you're doing wrong", or the historian who makes shibboleths of science, the textual critic who wants the scriptures to have no content; or the liberal who wants to turn it all into useless poetry and left wing politics, the fundie who wants to lick the text looking for the macrodot of right-wing acid, and instead is just left with a sour taste in their mouth because ink is not salvific.
As God did to Moses, so he did to the Church: imparting the meaning of the text: it's the Church's job to teach us. And our job to learn from her. Nowhere does any part of the scripture, read in the context of the rest of the text, say "You (singular, second person) can tell what this means." For God imparts the wisdom to "Y'all (plural, second person) by the Holy Spirit will be lead into all Truth." And it is in his Church, the pillar and ground of the truth, that "y'all" are.And the minute someone says "but wait... my Bible says..." you're in the wrong classroom.
If you want the truth: go to the source - which isn't the text, at all, but the Spirit of God living in his Church, and the Logos of God, spoken only once for all time in Jesus.