I think the whole "non-fraternization policy" thing is just an excuse to get him out due to AMD's success and market growth.
Not exactly his fault that AMD is doing well, what can he do about that. I agree that better management could have helped get 10nm out faster, as that is why were are still on enhanced Skylake.
Under Krzanich Intel has gotten more profitable than ever before, with 2018 possibly being its best year yet. 2019, however, is a little up in the air.
You say that it is an excuse, but its hard to deny that it is true. The guy has a Wife and a few kids, so there is no lie here. You would fabricate a more flattering story.
Breaking company policy is a serious offence, especially for a CEO, who has the ability to accelerate the careers of others and allocate bonus'. This is a Clarkson punch kinda situation, a line was drawn and crossing it has a consequence.
That being said part of me is glad to see him go, as he should have sorted out the manufacturing group's issues ages ago. We may soon have a 4th Generation Skylake-based architecture on our hands soon, that's not good. Intel should not have let TSMC get ahead of them.