A community call for moderator resignation or dismissal due to inactivity is based on a misunderstanding of the relationship between the community and the moderator.
Your view might be that people who run for moderator make promises of performance to the community if elected: promises which they have a duty to the community to fulfill. Perhaps you view moderators as elected representatives, and feel you have rights or vested interests as a member of the community that elects the moderators. From this perspective, a moderator who does not fulfill his duty to the community should resign or be dismissed.
Actually, the duty of a moderator is to Stack Exchange. A moderator is a Stack Exchange volunteer (which is what all of us in the community are). There is no close parallel between moderator campaigns and campaigns in other contexts (such as democratic government). Moderator elections are for Stack Exchange to find out which candidates are credible and best qualified to serve as moderators. A moderator campaign promise is a promise to Stack Exchange, not to the community. The role of the community is to decide whether the promise is credible. After election, it's Stack Exchange, not the community, that the moderator needs to satisfy.
Stack Exchange's inactivity policy helps provide clarity to moderators about what is normally expected of them, but it does not mean Stack Exchange automatically dismisses inactive moderators. Surely Stack Exchange is not looking for reasons to demote volunteers. In fact I imagine it's the opposite: they can use all the good help they can get. What interest would be served by dismissing a good moderator who goes on hiatus and communicates the fact to Stack Exchange?
In comment, you express the view that an inactive moderator stands in the way of giving a new user an opportunity to serve in his place. As far as I know, it is not a zero-sum game. Stack Exchange does not need to demote one moderator before it can appoint another. Moderators can be added or removed as needed.