What makes it feel like a big deal? Carbon, oxygen, and hydrogen are extremely abundant. Those molecules are relatively low energy combinations of the elements. I would be surprised to not find them in the atmospheres of big rocky planets.
Apperantly it seems to be the presence of " dimethyl sulfide ".
It seemingly only produced, on earth at least, by life. So using us as a baseline it seems pretty interesting.
> DMS is generated by the degradation of dimethylsulfoniopropionate, which is present in many species of marine algae and plants, including dinoflagellates and coccolithophores