Ok, I'll bite. What is your explanation, anyway? That "electric sky" nonsense
Actually, I think it's pretty obvious: the predictions related to gravitational attraction and/or the composition and mass distribution of galaxies (or both) is flawed, so those starting assumptions should be corrected first before some unknown and undetectable "other" is inserted into the model.
IOW, scientists shouldn't be looking for exotic "dark matter" particles. They should be looking for other examples of gravitational behavior across galactic distances and/or re-examining the way they calculate the mass of galaxies. The simplest explanation is that they have either under-estimated the mass or under-estimated the effects of gravity at those distances.
Multiple choice: you are given a large wooden box that is labeled "bottled water." You estimate, from the volume of the box, the maximum amount of water the box could contain and therefore work out what its mass should be. Then you try to pick up the box and find out that it's actually 80% heavier than you predicted. How did this happen?
a) You under-estimated the weight of the water
b) You didn't account for the weight of the box itself
c) There's something else in the box in addition to water
d) There is a second invisible box sitting on top of the first box that you cannot see or feel.
Any one of those explanations could fit the facts, but d) is the least plausible by far. They also have different solutions:
a) Check the actual mass/density of water and derive the results yourself
b) Check the mass of the box (or a similar box) without its contents
c) Try to find out for sure what is actually inside the box
d) Devise a series of stupendously convoluted and expensive experiments using setups so sophisticated that the raw data from the results would fill a three-volume encyclopedia.
Again, d) is the least likely to yield meaningful results, especially if you're starting from the basic assumption that there IS an invisible box and that the experiment will eventually bear this out, one way or the other.