I thought it was because for a while there was another group that met at the museum which scared everyone off including Canberra Cruises.
It's been pretty quiet there for quite a while but of course there's always more people when the weather warms up. I was there on Friday for a bit and some police turned up to drop someone off to their car that was parked there, checked out one or two of the cars and had a chat before leaving. It's still usually a nice relaxed crowd there.