How much is inspiration worth?

The Shabbos (Sabbath) morning service in the synagogue is really two services: Shachris, the morning prayers, and Mussaf, the additional prayers. Of course, if you have a rabbi, you generally have a speech. Where the speech falls in the service is a matter of personal taste.

Some rabbis choose to speak at the end, some speak between Shachris and Mussaf.

There are good reasons for the rabbi to speak at the end. For one thing, it doesn't interrupt the flow of things. For another, anybody who doesn't want to listen can leave. On the other hand, anybody who wants to come just to hear the rabbi speak can come late and skip the prayers (even though they are the whole point of things).

That leaving early thing is really great if the rabbi isn't. However, if you are lucky enough to have a rabbi who is a great speaker, he can truly inspire people through his words. If he speaks at the end, what exactly was that inspiration for? When a rabbi like that speaks in the middle, you can infuse your prayers with so much feeling it's almost like speaking to Hashem face-to-face. Why wouldn't anybody want that?