the real problem is that they don't simulate ocean currents yet so temperature is based on elevation and latitude.
It'd probably be difficult calculating said currents, and possibly even more on procedural planets.
computationally intensive and not to mention diving into completely irrelevant areas for a gravity simulator
currents would require simulating salinity, density, temperature (and thus insolation), and wind
idk if they want to go into that, I imagine not, but possibly parameterizing those things could allow for more realistic ice caps