It is not because "miracles do not happen," as in the dogma which Matthew Arnold recited with simple faith.
More supernatural things are _alleged_ to have happened in our time than would have been possible eighty years ago.

Men of science believe in such marvels much more than they did: the most perplexing, and even horrible, prodigies of mind and spirit are always being unveiled in modern psychology.

Things that the old science at least would frankly have rejected as miracles are hourly being asserted by the new science.
The only thing which is still old-fashioned enough to reject miracles is the New Theology.

But in truth this notion that it is "free" to deny miracles has nothing to do with the evidence for or against them.

It is a lifeless verbal prejudice of which the original life and beginning was not in the freedom of thought, but simply in the dogma of materialism.
The man of the nineteenth century did not disbelieve in the Resurrection because his liberal Christianity allowed him to doubt it.