in what way is it personal? In that he's attacking his conclusion for all of Kierkegaards' work? Or that he's trying to characterize your actions into a specific motivations?
Being called wrong , even in the softest ways, is now a personal attack?
I think it's fair to say that a 3-5 word sentence is a bit too shallow to characterize Kierkegaards' entire body of work. 'Sickness Unto Death' totally changed my outlook as a teenager reading it at the right time.
Here's the thing that's missing : life is as deep as we give it credit for, and many philosophies seek to enrichen and deepen the experience of life.
In my opinion, someone with the stance 'life isn't very deep' is in the perfect position to try to honestly absorb some of the pasts' philosophers and step away from the mammalian life of eat-sleep-breed.
In other words : our biological life is shallow in reason, philosophy and human thinking itself is what fills the world with reason, objective, and depth.
Anyone with the take-away that 'life isn't very deep' receives my greatest sympathy and sorrow. I remember how I felt when I came to the same conclusions, and i'm glad I have shifted away from that perspective with the help of philosophy and dialogue with others.
Re-imagining the world with the tools that philosophy gives you through practice is a fantastic experience, and I hope that the parent who believes that life isn't as deep as people give it credit for has the chance to undergo that epiphany themselves one day.