This is truly sad, and I could understand the outcry for them to stop keeping them.
However, it seems that the Public in general, needs to see something to conserve it.
I volunteered at a local aquarium for just short of 5 years (through most of my teenage years) and I saw that people had no idea about what was going on in the oceans, and cared even less, until they saw that 300 lb tuna swimming around, and the sharks that are caught in the nets and thrown overboard dying.
Its unfortunate, BUT I believe that in keeping these animals, and (even with good intentions) prolonging its death, if someone learned something, anything about these animals, its death was not in vain. It could have been a kid, who will grow up to be the next politician to cry for conservation. It could be an adult, who decides to tell all their friends about it, and in that stops the purchase of canned tuna, or the harvesting of whale sharks.
A marketing ploy? Perhaps. but in the end, even out of something as terrible as this, some good is bound to come out of it.
I know its been quoted already, but "In then end, you conserve what you love, you love what you know, and you know only what you have been taught..." holds true.
These aquariums are teaching something. And thats the only way that conservation can happen.
Just my 2 cents.