From Chabad.org: G‑d causes a wind to sweep in huge numbers of quail from the sea. The people gathered piles of quail and started enjoying meat. Those who ate gluttonously died in a plague. Miriam, Moses’ sister, spoke negatively of Moses’ decision to become celibate. G‑d was highly displeased by this talk against His servant, and Miriam was stricken with tzara’at (“leprosy”) for one week.
Once again we see actions personally justified that were wrong. Miriam spoke negatively about her brother, and while she felt justified, her actions/words were inappropriate, and she was punished. There’s a step between thought and action that seems to be the theme of this and the last Aliya. The thought might be true and accurate, but there needs to be a clear and objective thought process that leads to any action. If you feel Moshe is doing something wrong, think about how to best deal with that. Although her actions correlated to her thought, it was inappropriate. So she learned her lesson, as did the Jews, as should we. When we feel strongly about something, the actions caused by that idea or ideal needs to be objectively correlated and proper.