Even after experiencing great miracles in the desert, the Israelites maintained a pattern of defiance. The life-saving water they received had already been born out of sin and complaint, yet they continued to provoke God rather than trust Him [רד״ק, מצודת דוד]. Their actions were not mere stumbles, but deliberate acts of rebellion meant to anger Him [רש״י, מצודת ציון, שטיינזלץ].
The primary approach among commentators is that the core of this rebellion was a deep-seated doubt in God's ability to provide for their needs. The people tested God by demanding meat, assuming He lacked the power to supply it in such a barren place. Had they truly possessed faith in His capabilities, they would have turned to Him in prayer rather than voicing bitter complaints [מאירי].
Rebelling against the Supreme Being highlights the sheer absurdity of their actions. God controls all of existence; if He could draw water from solid rock and drop food from the sky, He could easily provide meat [רד״ק]. However, the Israelites were still heavily influenced by the pagan ideas they had absorbed in Egypt. They believed that the ultimate Creator did not involve Himself in the daily details of the world, leaving such matters to lesser, natural forces. Because of this mindset, they mistakenly viewed the God who performed miracles for them as merely a limited, local power, completely denying His direct, ongoing care for them in the desert [מלבי״ם].
The setting of this rebellion—a parched, desolate wilderness—adds a complex layer to their actions [אבן עזרא, מצודת ציון]. On one hand, rebelling in such a harsh environment magnifies their ingratitude, as they chose to defy God in the exact place where they depended on Him most for survival [אבן עזרא]. On the other hand, the location itself offers a measure of defense for the people. The desolate wilderness was an environment dominated by harsh spiritual impurity, and simply existing in that dark atmosphere negatively influenced the Israelites and dragged them into sin [חומת אנך].