I get that people like Phoenix and all...but I don't understand why people have trouble when the games start to focus on other characters. As far as the ebb and flow of cases go, all three of the attorneys go through similar bouts of confidence, defeat, inspiration, frustration, pulling solutions that turn out to be correct out of their ass, and so on. And in the macro view of overall character development...Phoenix is kind of a finished product by now, isn't he? We've seen how he grew up, why he decided to become a lawyer, how he met his mentor, how he got his start in law...we've seen him handle an imminent crisis about what it means to himself to be an attorney in AA2, saw him confront his most personal demons (somewhat literally) in AA3. In 4 we witnessed both his maturity and his overconfidence in the skills he'd amassed during the first trilogy, he paid for his mistakes, and by the end of the game found a way to turn the situation around and reclaim much of the honor he'd lost.
Now in this game we see him continuing to cope with his new role as a mentor and a "boss," trying to pass his way--Mia's way--onto the next generation. What more is there to learn about Phoenix Wright and why he stands in court at this point? There's still much more to Apollo and Athena's stories to be told and I like that this game showed both of them developing in their own ways. I'd love a potential AA6 to continue digging into the dynamics between the three of them, rather than cutting back to such a big focus on Wright.