[1][2] The statement exemplifies a red herring or thought-terminating cliché.
Where an objection to a belief is made, the assertion of the right to an opinion side-steps the usual steps of discourse of either asserting a justification of that belief, or an argument against the validity of the objection.
[5] Philosopher Patrick Stokes has described the expression as problematic because it is often used to defend factually indefensible positions or to imply "an equal right to be heard on a matter in which only one of the two parties has the relevant expertise".
[6] Further elaborating on Stokes' argument, philosopher David Godden argued that the claim that one is entitled to a view gives rise to certain obligations, such as the obligation to provide reasons for the view and to submit those reasons to contestation; Godden called these the principles of rational entitlement and rational responsibility, and he developed a classroom exercise for teaching these principles.
[4] Philosopher José Ortega y Gasset wrote in his 1930 book The Revolt of the Masses: The Fascist and Syndicalist species were characterized by the first appearance of a type of man who "did not care to give reasons or even to be right", but who was simply resolved to impose his opinions.