Agreed, this has repeatedly been one of the biggest failings in communicating the reality of anthropogenic climate change.
Climate change is not a single event, nor a cluster of events, that occur(s) over a summer. Strong hurricanes have occurred well before Dorian [1]. So have heat waves [2].
Extreme weather happens. The change in the frequency of (some) extreme events can be attributed to anthropogenic climate change, but a single event cannot.