  Recent high resolution spectroscopic analysis of nearby FGK stars suggests
that a high C/O ratio of greater than 0.8, or even 1.0, is relatively common.
Two published catalogs find C/O$>0.8$ in 25-30% of systems, and C/O$>1.0$ in
$\sim$~6-10%. It has been suggested that in protoplanetary disks with C/O$>0.8$
that the condensation pathways to refractory solids will differ from what
occurred in our solar system, where C/O$=0.55$. The carbon-rich disks are
calculated to make carbon-dominated rocky planets, rather than oxygen-dominated
ones. Here we suggest that the derived stellar C/O ratios are overestimated.
One constraint on the frequency of high C/O is the relative paucity of carbon
dwarfs stars ($10^{-3}-10^{-5}$) found in large samples of low mass stars. We
suggest reasons for this overestimation, including a high C/O ratio for the
solar atmosphere model used for differential abundance analysis, the treatment
of a Ni blend that affects the O abundance, and limitations of one-dimensional
LTE stellar atmosphere models. Furthermore, from the estimated errors on the
measured stellar C/O ratios, we find that the significance of the high C/O tail
is weakened, with a true measured fraction of C/O$>0.8$ in 10-15% of stars, and
C/O$>1.0$ in 1-5%, although these are still likely overestimates. We suggest
that infrared T-dwarf spectra could show how common high C/O is in the stellar
neighborhood, as the chemistry and spectra of such objects would differ
compared to those with solar-like abundances. While possible at C/O$>0.8$, we
expect that carbon-dominated rocky planets are rarer than others have
suggested.
