[Inziladun]

Is this a serious question?

Gandalf was the accepted leader not only of the Fellowship, but as far as Aragorn was concerned, the struggle against Sauron. Aragorn had been a pupil and friend of Gandalf for many years. He questioned the decision to go to Moria both out of a personal bad memory of a prior journey, and a foreboding that Gandalf would meet some peril there. His reluctance was not based on any lack of faith in Gandalf as a leader or a guide.

And also, by what authority could an "arrest" have been made? That's lunacy. At most, any member of the company who wished was free to stop following Gandalf and go their own way. It's notable that none did so. Gandalf retained their trust even under the direst of circumstances.