"Planets lack mass".... How many planets. If they're more common than realized in interstellar space, which is consistent with the numbers being found as our telescopes improve, there is plenty of space between stars to hold stellar masses worth of rogue planets. If they exist in even modest numbers in inter-galactic space, they'd be impossible to detect with current tools except by... let me think, what was it we were talking about??? Oh, yes, gravitational effects, which in no way require non-baryonic matter. They simply require matter that is not easily optically observed, or apparent to radio telescopes. Hmm, let me think.... what could hold large amounts of matter, far more than could be measured optically, but with no need for inventing physics based on nothing?? Cold rocks, you say, the ones that keep turning up even in our local stellar neighborhood as our telescopes improve?
Nahh, we couldn't have an extremely mundane explanation for anything that generates funding for untestable hypotheses and extravagant, physics shattering theories like string theory and multi-dimensional folded matter based on nothing but the fantasy of people who wouldn't know an error bar if they were forced to sit on it vertically.