The same reason why most people like to watch a movie in one go, instead of watching the first half now, and the second half in three months. I like these episodes to be a somewhat contained piece with a satisfying little story arc and an ending that fits. Randomly cutting it in half will just feel unfinished. I'm sure some would disagree, but that's how I'd like to continue doing this.
It's also just a lot easier (for me) to write the whole thing, then do all renders, and then test and polish until everything fits, instead of dividing that into 2 or more partial episodes. Another thing is that there's always a sort of balance in an episode. Between the 3 routes, between story parts and sex parts, between funny and serious parts, and so on. Cutting it in half might mess with that as well.
And lastly, each release still comes with a lot of time that is needed for a bunch of stuff. Polish, building distribution files, uploading files, social media posts, and just generally a lot more distractions since I spend a lot of time reading feedback and interacting with the community after a release. So the second release would just be pushed back and you'd ultimately wait longer for the full episode to be out.
(And yes, more frequent updates would most likely be more profitable. But I'm just gonna pretend that avoiding negative rep for releasing unfinished episodes will make up for that in the long run

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