Why was it imploded at such a young age? It was imploded in part because it was too big and had too few* luxury boxes. It was also obsolete. Why was it obsolete? Because politicians built the Charlotte Arena for $265 million dollars in part to lure an NBA franchise back to Charlotte. The Hornets left Charlotte in part because a new publicly-funded arena was not forthcoming quickly enough.
In some Utopian sports society, where the separation of sports and state are clear, would the Coliseum have been torn down at 19 years of age and would it have been built so big in the first place?
This seems to be one of the things Milton Friedman had in mind when he warned us about spending other people's money on other people.
*Thanks to commenter Frank for noting that I had written the arena had too many luxury boxes when I originally wrote the post