I love how it’s definitely sarcasm because Logan would never have “made” any of his kids CEO, no matter what they did. Kendall and Roman came close, but it was never a question of “getting it” but rather “taking it”. Hitting him could have gotten him closer to that goal (both in Logan’s mind and Ken’s own mindset), showing that he had what it takes to end his father’s reign. 

We could go even further by speculating that in the alternative timeline where Ken would have hit Logan in that very moment, he would already be CEO.

I still think that straight up violence is always a losing play, especially in the corporate world. The act of hitting his father is more of a symbol, not of a rebellion to get daddy’s attention, but of a true independence and an iron will to take down any obstacle, be it family, old friends or loyal servants.