Did the suffragettes not believe in democracy?
A better example is the Civil War. The southern states refused to accept the free and fair election of Lincoln and decided to secede, which was not allowed by the Constitution.
Are you arguing that the Confederates were right to violate the law just because they believed they were right?
Have you not heard of the labor movement? Or abolitionists? Or the founding of this country? Or people fighting against Nazi control of their country?
All of those worked outside "legal" means. The law is quite often irrelevant to what's right or moral, and dying on the hill of breaking the law ensures no change can ever occur when a system or person in power inevitably wrongs people.
But throwing Molotov cocktails is terrorism. And I don't believe (please correct me) that a terrorist has ever gotten new laws passed by using terror.