In my opinion, yes, remote sensing should be fully covered by geoscience.
Therefore, the Remote Sensing proposal should be closed as a duplicate.
I think that SR is indispensable, because if you don't have information about the phenomenon you never may made an appropriate analysis because you don't have in mind all variables that could be relevant for any study, to sum up the database that you get from SR is information that you can't avoid.
I think it is not good to have RS in Geosciences. RS is a method to acquire data which can be used in oceanography, ecology, archeology, agriculture, architecture etc. Like GIS is a tool to analyze and manipulate geodata (including data obtained by RS), and all geosciences use GIS a lot. But GIS stackexchange is a separate site (and appeared long before Geosciences). So I think RS should be or a separate site or inside GIS where it is now. Not to mix tools and applications.
On the chat of GIS.SE someone mentioned that in China, they have a term called "3S" which refers to (GIS, GPS, RS). Would it be better to have a site called 3S SE which including questions in GIS, GPS and RS?