I think some Ai's fans are too much. Real Ai's fans think the ending was the real treat. It includes the game's story from Ai's three routes.
The story of Amagami is good as way it is. I don't want to see some unpopular twist as Kimikiss anime, where Mao was popular enough to dethrone the main heroine. The result was the outrage from fans.
So, Tsukasa is the main heroine. So, be it. She's good in her own way. Besides, each heroine's story is self contained. There's no single heroine dominating other heroines. What's wrong for putting Tsukasa at the center of photo shoot?
By the way, it may be just me. I think the outdoor sox in hot spring is going to boost DVD/BD sales. It' not I'm complaining about it. When watching the hot spring sequence, can't stop hearing clapping/air pumping sound in my head.
Yes, DVD/BD sales is what producers cared. More fans like the story, the better sale. In this case, the anime is quite faithful to the game.