It's the relative energy scales in the system that matter. You can e.g. compare the superconducting energy gap to a temperature, for Niobium the gap is around 2.3 meV which corresponds to about 27 K. For high Tc superconductors the story is a bit more complicated but their pseudo gap is 5-8 times higher, hence around 150-200 K. Niobium has a Tc of 10 K, high Tc superconductors (unpressurized) at most 150 K. What's safe to say is that if the temperature becomes significantly higher than the energy gap the superconducting state will be lost as there's thermal tunneling out of the state and it becomes thermodynamically "unfavorable" (this simplifies things). Now there's no reason that we couldn't find a system with a larger energy gap but that gap itself is defined by other properties in the system that have constraints on their own. Fundamentally there's no reason that there couldn't be a system that fulfills all these constraints at room temperature, but there isn't a reason why there should be such a system either. Then again there might be different superconductivity mechanisms that we don't know about yet and that we could exploit, but I think it's not very likely that we'll find a regular material system with these properties because there are not that many crystal lattices to choose from and we've been looking for more than 50 years.