I wouldn’t want to be in a church fellowship, where only one topic was preached week on week, no matter what that topic. Stewardship, anyone?
We are slightly challenged in our fellowship in that we teach from a sermon series rather than a lectionary, so there will be some kind of common theme for six weeks or so. However, we manage variety. Even if one of our preachers has a bee in his/her bonnet about an issue, we have have 7 other preachers who can modify matters.
Politics and activism should be important to Christians. Both politicians and Christians are tasked to speak up for those who cannot speak up for themselves.