Yes, I agree. In the Humanities, class can be quite important. It also depends on the type of MA you are doing. In my program, we had two options: a thesis-based MA or a course-based MA. I did a course-based MA, so class attendance was really of utmost importance. That is not to say that my classmates and I did not miss class once in awhile for reasons like illness and conference attendance. For example, at least once a term, I missed a class to present at a conference. I discussed why I would be absent ahead of time with my professors, who were very supportive of my conference attendance and helped me prep my conference papers so they would be presentation ready.
But, to really emphasize how important class attendance was for my particular MA, one of my dear friends and colleagues doing the course-based MA was denied admittance to our department's PhD program and the reason given by the department? Because she had missed class too frequently for a course-based MA student and, thus, the department questioned her commitment to her studies. Now, when she had missed class, she had missed for research reasons (a.k.a. to attend conferences or talks that were in line with her area of research), and she had only missed a few classes a term. Yet, as the department head told her, it was a course-based MA and, therefore, course attendance was crucial. Since she had committed to the course-based MA, she needed to commit to her classes first and foremost.
That all being said, can you miss class once in awhile? You can. But do keep in mind that unforeseeable circumstances can happen that may prevent you from attending other classes in the future.