I have my own theory on dark matter, every ying has a yang, a positive & a negative. I think the reason dark matter is so elusive is because we have yet to discover the medium in which to view it, the known light spectrum i think has a mirror beyond what we can already see in either viable or invisible light.
I think once we discover these new spectrums everything that is hidden will be illuminated.
It must stand to reason if dark matter exists then so does dark energy, who is to say that when or if we reach a point when it becomes visable that this dark matter has not coalesced in to dark suns, words, solar system or even galaxies. May be the gaseous arms of our own milky way as we see it is not the full picture & when it is finally revealed in all its glory a few hundred billion sun's will become so much more.
Crazy notion i know but i can dream.