Why would Kamiya block anyone for talking about Capcom?
Because Capcom and P+ are still friends. The staff at C and at P+ have no animosity for each other, they are still in speaking terms and have never had bad blood. When Clover left C they had their blessings and it's not as though anyone else would stand by while people talk smack about their friends. He's blocked people for less.
Would anyone have a legitimate reason to complain about Capcom to begin with?
Capcom have a very checkered history and their bad reputation has been hanging on them for a long time. For years they seemed to be doing nothing right, bad policies, terrible use of their IPs (ORC, anyone?), and they were a prime example of everything that was wrong with the industry during the 7th generation. It's a reputation they've worked very hard to get passed.
Why silence them, unless they had points that both he and Capcom refuse to address?
Because he's done so for less. Again, someone talks smack about your friends it's normal for people to get defensive.
Why bother defending a faceless corporation who only sees you as just another wallet?
Because to him it's not faceless. He worked with those people for decades and while no one at Capcom is as infamous on twitter as Kamiya is I have never seen any sign of malice from one to the other.
