Wouldn't the most realistic hard planet be
"Iso122
Planet is composed mostly of plagioclase feldspar, cumulate rock, and various silicates and contains a molten iron/nickel core. It lacks an atmosphere and and no longer generates a magnetic field powerful enough to shield it from solar winds. Several deposits of rare elements have been discovered in its crust but no organic molecules have ever been discovered. Surface temps fluctuate between 745K and 120K. "
Considering that most planets are just hunks of rock without much interesting on them.
You'd be surprised. That sounds like a planet fairly close to a star (of which, of course, there are some), but surprisingly quickly you get out to the point where the surfaces are mostly ices (water ice 'close' to the star, then carbon dioxide and methane, and then other gasses) rather than rock, since their atmospheres (or what would have been their atmospheres) freezes to the surface when you aren't talking about the habitable band. Additionally, carbon is reasonably common throughout the universe, as is water, and so it doesn't seem unreasonable to have some kind of self-reproducing stuff on planets that do form within the habitable zone, along with some reasonably basic similarities to earth life (For example, some sort of solar energy harvesting organism, some way to regulate internal environment such as either ectothermic behaviors or endothermy, and some sort of food chain - why bother gathering energy yourself when there are all these concentrations of stored energy around? Heads or distributed nervous systems in larger animals are also reasonably likely, because nerve length between sensory organs and the brain is directly proportional to reaction time).
Now, we can argue about the probabilities of planets that can sustain life as we know it, but from what we've observed thus far we have 1/8 planets that will support life in our own solar system (and 1/4 non-gaseous planets), and as we refine our observations of other stars we are seeing that stars with planets aren't uncommon, and that 8 is a bit high but not abnormally so. But that in and of itself can be balanced by the fact that we're looking for the interesting planets, and the ones with life (or the potential for life) are the interesting ones: For every Brahe II, Aurora, or Chasm there may be tens or hundreds of Iso122s, but that still leaves a lot of garden worlds around.
As balance, though, I'll contribute Brahe IV (yes, I made a whole solar system: one star, eleven planets and one asteroid belt. Brahe IV is the third most habitable, by the numbers), phrased as the colonization feasibility report made by the Dyson upon arrival in the system.
Brahe IV, orbiting at 1.02 AU with a diameter of 8800km and a significant moon, would ordinarily be seen as an ideal colonization candidate. However, Brahe's low luminance means that Brahe IV has an average surface temperature of -50 C, a surface covered in water ice, and an atmosphere that, while reasonably dense, is essentially devoid of oxygen. Surface gravity is estimated at .7G. Colonization would be possible, but would require a significant investment - heating would be required and a stable supply of oxygen would be needed (though oxygen compounds such as carbon dioxide and sulfur dioxide are present in the atmosphere, so gasses would not need to be imported). Although the thickness of the ice and the precise surface composition are unknown, the ice is believed to be no more than one kilometer thick and density measurements indicate that the surface is rocky with a nickel/iron core. Once again, a subterranean colony would likely be the most viable option, likely tunneling through to the surface both for construction materials and to avoid the dangers of melting the surrounding ice through heat-producing activity. Brahe IV is not thought to harbor any native life.
