Origin of CMBR?

Here is an interesting video about the possible origin of the Cosmic Microwave Background Radiation CMBR other than an "afterglow" of a Big Bang proving the Big Bang hypothesis to be correct, as the currently most popular cosmological theory:  

The video recalls early theories about a static Universe filled with some form of interstellar dust radiating a Planck spectrum of around 2-5 Kelvin. Such a thing was detected in 1967 at 2.7 K and was then  connected to Big Bang deleting the old theories from the map. In particular the Big Bang theory claimed to resolve the mystery of the observed red-shift of galaxies increasing with distance suggesting an accelerated expansion of the Universe. 

One of the old theories was the "tired light" hypothesis presented by Zwicki in 1929 suggesting that the red-shift could be the result of a loss of energy of light passing through interstellar dust over long distance with energy scaling with frequency.  

The idea of an active interstellar dust actively radiating at 2.7 K seems more natural than that of a Big Bang "afterglow" still hanging on after 13.8 billion years. 

Zwicki's "tired light" hypothesis can be connected to some form of dark matter as source of gravitation which shows up as CMBR resulting from sucking up energy from passing light.  I have discussed dark matter in posts on Neo-Newtonian Gravitation.