I hope you enjoyed your stay at the Key Café. We’re not exactly talking about a medium that’s known for being concise here. Don’t agree with you about the filler part—all the time Tomoyo and Tomoya spent hanging out with Sunohara is possibly my favorite part of this route. The three make a great group and I enjoyed their time together just as much as they did. You can’t really expect the route to be jam-packed with feels from start to finish; the route is more than just the climax, but that seems to be the only part you care about.
Please forgive the high school girl for not being a strict workaholic 24/7. This is one of her major internal conflicts: she has something she needs to do but she’s distracted by her infatuation for Tomoya. That’s exactly why she breaks up with him, because she recognizes that their relationship is preventing her from saving the trees.
I mean, that’s exactly why she does it. Right after hearing about her brother, she shouldn’t even need to say explicitly why she’s saving the trees.
I used to be in a place where I hated happy endings too. That ending is so shallow I can’t agree that it’s better at all. There’s no growth on the part of anybody in that; Tomoyo utterly fails in all she holds dear and only serves as a tragic love interest.
Tomoyo is the one who grows the most in this route. That’s not to say Tomoya is only an observer here, but Tomoyo really does choose her own path.
Don’t forget that ultimately, Clannad is all about family. It’s right in the name. The game isn’t just a simple love story; there’s highs and lows, fun times and difficult times for each character. The characters grow even if things don’t always work out perfectly for them. If a regular love story or an overly melodramatic tragedy is what you’re searching for, you may be better served by a generic romance novel you may find at a department.