What Miriam and Aharon did not appreciate about Moshe Rabeinu is that "temunas Hashem yabit." Netziv explains that Moshe Rabeinu did not see things the way an ordinary person sees things. There is a way if looking at things that is G-dly, that is special.
I think that is the connection between the parsha of Miriam speaking against Moshe and the parsha of the meraglim. It's not just that both spoke badly. It's that the meraglim failed to take heed of the fact that there is a way to look at things that goes below surface impressions. When you look at something holy like Eretz Yisrael you need to put on the glasses of "temunas Hashem yabit" or you may miss the picture completely.
If you don't see the kedushas ha'aretz, the singularity of the land, it is a pgam in your vision, not in the land.