Eichi wants to grow ES because it's his company, his childish fantasy that he will stop at nothing to obtain. Ibara is ruthless and a tactician, but he isn't delusional and idealistic like Eichi. Eichi pictures what he wants and starts slashing down everything in his way to get there. He uses the corpses of the people he has crushed like a staircase in hopes he will one day climb high enough to achieve his personal dream world. That's why he is doing these things. The other thing is, Eichi has been somewhat flippant about preservation of and respect for cultures for a while. He once said to Keito that he would burn down the Buddhist temples. Obviously, this didn't happen, but it's a cruel threat he made because he knows Keito is Buddhist and that the religion is important to him. Oh, and lastly, I'm not a fine-p, but I've heard from a friend that even Wataru is growing frustrated with Eichi's stagnation. In other words, the writers are self-aware. They know what they are doing.