Not to be missed among the many views of what Moshe did wrong at Mei Meriva is the opinion of Yalkut Shimoni (remez 564):
יען לא האמנתם בי ארבע חטאות כתובין כאן לא האמנתם, לא קדשתם, מעלתם, מריתם, לא האמנתם שלא אמרתי לכם להכות והכית אותו. ולא קדשתם לעיני כל ישראל להוציא להם מים מכל סלע שרוצים, מעלתם אמרת המן הסלע הזה, מריתם ודברתם אל הסלע שנה עליו פרק אחד ועברת על דברי.
The sin of “not speaking” according to the Yalkut does not mean not ordering the rock to produce water, but rather refers to the sin of not studying Torah near the rock. Moshe should have responded to the demand for water by sitting and learning! Hitting the rock to produce water undoubtedly demonstrated Hashem’s miraculous power, but it did not demonstrate the power of Torah, and it was for that specific crucial failing that Moshe was blamed.
There is much to learn from this Yalkut. Imagine the criticism a leader would face if after hearing of the people's needs and demands he would retreat to the beis medrash to sit and learn. The headlines would decry the callousness -- He doesn't care! He's not engaged in the world! But that's exactly the response the Yalkut sees as appropriate. Where else can we find guidence, what greater power can we bring to bear on a problem, if not the merit of Torah study?
Consider about whom the Yalkut is speaking – is there anyone who we can say embodied love for Torah more than Moshe Rabeinu? Is there anyone whose life was devoted to teaching Torah more than Moshe Rabeinu? Surely Moshe was the paradigm of what a Torah scholar should be. Nonetheless, Moshe is not spared criticism or punishment for failing in this one instance to impress upon the people the power of Torah.
We are not Moshe Rabeinu, but the responsibility rests with us as bnei Torah to reinforce to our families and others the awesome power of limud haTorah. "Ain mayim elah Torah" -- if we are diligent in our learning, even the dry rocks will be inspired.