The spire was rebuilt in the 19th century because the old one had fallen apart. As far as I can tell from Wikipedia, it was a replica of the original one.

As for why people are talking about redesigning it? I think this is down to Europe's rejection of classical art and craftsmanship, whereas in the United States, imitating classical art remains popular. That's what American 2D animation studios such as Disney did, for example. The only art school in Italy that teaches Renaissance painting techniques was set up by Americans. Go figure.

To a European who views himself as a cosmopolitan with sophisticated tastes, creating such pastiches is seen as vulgar and even grotesque. The past must be rejected. Post-modernism, abstract art and oddly shaped buildings, is where it's at now.

I'm from Europe myself and I reject this bizarre way of thinking and admire the old masters. Judging by all the hideous architecture being created, however, I am swimming against the current.