I honestly don't see the problem.
If you buy either Birthright or Conquest, you'll get 28 main chapters plus some amount of side chapters (I'm assuming 13 from your graph).
For a comparison, the previous Fire Emblem games had
Awakening: 26 main chapters + 23 side chapters = 50 chapters
New Mystery of the Emblem: 25 main chapters + 7 side chapters = 32 chapters
Shadow Dragon: 25 chapters + 4 side chapters = 29 chapters
Radiant Dawn: 42 chapters
Path of Radiance: 30 chapters
Sacred Stones: 21 chapters + 9 alternate route chapters = 30 chapters
Blazing Sword: 31 chapters + 6 alternate route chapters + 6 side chapters = 42 chapters
Binding Blade: 25 chapters + 4 alternate route + 5 side chapters = 34 chapters
Thracia 776: 25 chapters + 2 alternate route + 7 side chapters = 34 chapters
So, the first Fates game you buy will have more chapters than any Fire Emblem barring Awakening, Radiant Dawn and Blazing Sword. It's most likely longer than Blazing Sword too, considering it had a large amount of extremely short chapters.
Then, with the second version you buy, you get roughly half as many chapters as the longest Fire Emblem games, at roughly half the price.
If you then buy the third version, and then after that somehow manage to feel that you've been scammed out of your money, then you're an idiot.
As someone who thought Fire Emblem was gone and dusted after Radiant Dawn performed poorly, and the not-quite-so-good DS games performed roughly as bad, I'm extremely pleased with getting a Fire Emblem game that's in size roughly 2.5 times the size of a normal Fire Emblem game. Having to pay twice the price of a normal Fire Emblem game doesn't seem so bad, because I'm getting more Fire Emblem.