I feel this is because of the education I have received, or rather, not received. Many of my college Spanish classes have been teacher centered. Although we hear Spanish the entire hour, I feel we have little opportunity to work on our speaking skills. I don't feel this has prepared me enough to teach in the target language. I think it is the teacher's responsibility to expose the students to the foreign language as much as possible from the very beginning, but I wonder how many first year teachers are really prepared for this.
Communicative competence covers a broad range of elements.
I think the university should better prepare foreign language teachers by including more speaking classes. So, yes, I think foreign language teachers have a responsibility to be communicatively competent, but many fall short of this. When the teacher talks and the students listen, that is not communication. Students don't get a chance to respond and they may not even be listening at all. I was terrified to speak in my Spanish classes before I spent a summer in Mexico.