> Yes I know the theory makes some predictions that have turned out to be correct
However, I must say that once P. Steinhardt gave a seminar in my department, and he debunked two famous "predictions" of the inflationary theory (flat universe, scalar index n_s slightly less than ne) showing that papers published in the 90s claimed that inflation predicted "naturally" an open universe with a scalar index larger than one [1]. He used this to stress the fact that inflation can predict almost everything. I must say he sounded very convincing, he wasn't claiming that inflation is false, only that it is far from being a well-established theory, and that other hypotheses must be considered as well.
However, I must say that once P. Steinhardt gave a seminar in my department, and he debunked two famous "predictions" of the inflationary theory (flat universe, scalar index n_s slightly less than ne) showing that papers published in the 90s claimed that inflation predicted "naturally" an open universe with a scalar index larger than one [1]. He used this to stress the fact that inflation can predict almost everything. I must say he sounded very convincing, he wasn't claiming that inflation is false, only that it is far from being a well-established theory, and that other hypotheses must be considered as well.
[1] http://physics.princeton.edu/~cosmo/sciam/index.html#facts