The World said
Background radiation.
Your Background Radiation "Bumps" are getting too low to create galaxy clusters within billions of years. For another thing, another plausible cause of this is large intergalactic clouds of gas colliding with each other. The radiation scattered would be interpreted by the COBE satellite as those "Bumps".
In fact, these "Bumps" are perfectly smooth. Our universe is clumpy, which means that the Cosmic Radiation should be clumpy, but no, it's
perfectly smooth. Then they tried to find temperature data that could keep their theory going, but the data they finally found was too small to account for the clumpiness. All in all, background radiation actually works
against the Big Bang Theory.