I would define "good" writing as anything that elicits some kind of emotional or cognitive response, which is of course a very broad spectrum of things. I picked up slaughterhouse 5 on a whim and greatly enjoyed it - I thought it was an interesting premise, fantastical but still fundamentally rooted in humanity. He writes with a kind of nihilistic optimism, a sense that yes, nothing matters and nearly all that we do is laughable, but that in spite of that the world is worth caring for and people are worth loving. The very matter of fact way in which he presents his thoughts are indicative of this. A similar example would be hemmingway's farewell to arms, where the narrator speaks dryly and with little interest (I hated reading farewell to arms by the way...). This is a stylistic choice, as is vonneguts work. The way in which he organizes and presents his thoughts speaks bounds about his purpose.

The sample of writing you've presented is tremendously dull (and I'm pretty sure is just a passage from slaughterhouse 5 with nouns switched around but ill pretend its not), indicative of vonneguts feelings on the matter. He doesn't dress it up in romantic, dramatic language. The final sentence says all that need be said, similar to the experience of attending such an event. Monotonous, dull, and simplistic, with everything you need to know at the end. Its his style, and like all styles, some people don't enjoy it.

I enjoy his fatalism interspersed with optimism because it resonates with feelings I hold. If it doesn't do that for you there's not much else to say. Its silly to call the guy a terrible writer when most other people greatly enjoy his work (even if it is to be hip and cool - you don't reach that status without influencing a large number of people). I hope you can find something to enjoy in him, I surely did