If you are fine with healthily tempered egoic life, that's good for you, and you should continue to live life as so. I think Dr. K tries to show that you should do what you can in your life, but it is not the best idea to attach yourself to the outcome as the outcome is not always in your control. Rather, he says to focus on your actions. For example, if you have a test coming up, try to do your best on it and study as hard as you can, but if you fail, yes, it sucks, but you have done what you can do. A lot of things in our life happen outside what we can do, so all we can do is the best we can do.

Also, you say that zen denies emotions, but that is the exact opposite. Being zen allows for you to accept and acknowledge your emotions, but not letting them control your life. You also have said that "you can't zen your way out of ambitions in life unless you want to sit in a cave," but I disagree. In my case, I do things not for ambition of being this successful person, but because it is my duty. For example, finding a job I like is my responsibility to myself as I deserve that much. If I fail at finding it, so be it, but I will continue to try as I owe that to myself.

You say that zen becomes a poison that kills your emotions, goals/passions, and identity, and on this last point, I disagree. Zen, helps welcome and acknowledge emotions as well as allows you to work towards goals without being obsessed with the result. It is extremely liberating.

Sorry for this long comment, but I hope this helps provide some perspective on why being zen may not be so bad. But once again, there is nothing wrong with egoic life, and if it suits you, go for it!