Either they don't generate or they're just extremely rare.
Tips for finding Earth-Like planets: Look for F, G, or K Class stars. M class habitables will almost always be tidelocked. Oceanias can, of course, also be habitable, they just have tiny amounts of land.
Carbon and zirconium stars are actually very unique so they don't generate(yet).
Wolf-Rayets don't generate procedurally, and I find this extremely strange since I personally see no reason not to generate them(Is SpaceEngineer waiting to implement proper variable star support first?)
As for hypergiants, red hypergiants actually do generate, but they are very rare. The main problem I noticed is that any spectrum other than red(orange,yellow,white and blue) doesn't generate as a super/hypergiant, so there aren't any blue supergiants or white hypergiants, for example.
ok cool. I wasn't sure if they didn't generate or were just extremely rare. I figured because WR stars and hypergiants are some of the most visible around the milky way, yet the brightest stars in other galaxies are all main sequence, that they didn't generate procedurally.