Do you think that fbi agent is working for someone else?

But then there'd be fewer episodes to spread over the remaining 4 1/2-5 months of the season in 2018; and it's already spotty during the non-sweeps periods, often with a stray new episode sandwiched between two or three weeks of reruns, making for a uneven play of the story. And this will invariably leading to at least one person asking why they're scheduling this and every show like that, like it was something new.

They could probably go one more week, but the last two weeks of the year are typically a very busy time for a lot of people; and the CW (and most other networks) no doubt figure it's not worth broadcasting episodes people don't have time to watch right now.

It is interesting how everyone now frames these last episoded of the calendar year as "midseason finales", and even treats them as you might treat a season final. Just a couple of years ago most shows didn't look at their season that way, they didn't call it finale, and often I don't think they did much in the way of even punctuating the stories at the midway point; it was just where the series broke for the holidays and audiences were expected to remember where they left off.
I think the rise in popularity of basic cable original shows, which had an even more divided structure of breaking halfway through a season, only to come back months later, sometimes 6 months or more, changed how other networks looked hothey framed their schedules. Of course the next trend to become popular is to not even pretend like they're two halves of one season, but two full, yet abbreviated, individual seasons; each consisting of roughly 12-15 episodes. This has not only become popular for cable networks, but also streaming networks that release an entire season at once; making it more suitable for binge watching. And I have been thinking recently that it might not be a terrible idea if these shows did go to shorter seasons; which often allows writers to tell a tighter story. Agents of Shield have embraced that idea to a degree; even though they still run a full broadcast network season, their arcs that start at the beginning of the season have started concluding by the middle of the season, breaking at at segue into a new story arc that will conclude the rest of the season when they come back; and they often take longer breaks, so the remaining episodes can run uninterrupted. I'm not sure what this year has in store, since they only just aired their season premiere.