As much as I love the tv and film adaptations of the Musketeer stories, they never capture the characters and the mannerisms associated with them that are front and centre of Dumas' original stories.
"And while we are on this head," said Aramis, "you also are a malcontent; you also, Raoul, have griefs to lay to the king. Follow our example; pass over into Belle-Isle. Then we shall see, I guarantee upon my honor, that in a month there will be war between France and Spain on the subject of this son of Louis XIII., who is an Infante likewise, and whom France detains inhumanly. Now, as Louis XIV. would have no inclination for a war on that subject, I will answer for an arrangement, the result of which must bring greatness to Porthos and to me, and a duchy in France to you, who are already a grandee of Spain. Will you join us?"
"No; for my part I prefer having something to reproach the king with; it is a pride natural to my race to pretend to a superiority over royal races. Doing what you propose, I should become the obliged of the king; I should certainly be the gainer on that ground, but I should be a loser in my conscience.— No, thank you!"
"Then give me two things, Athos,— your absolution."
"Oh! I give it you if you really wished to avenge the weak and oppressed against the oppressor."
[The second request is for fresh horses ... in case you were wondering.]
It never really becomes clear in the films and tv series that Athos, the Comte de la Fere, has objections to royalty. Perhaps it would cause too many questions and take too long to reconcile with the various tales that focus on the Musketeers' loyalty to the king and the institution of the monarchy.
The contradiction and the various motivations of the characters in the books, however, is what makes the stories so much fun.