Folks need to study the evolution of whale shark interaction in Donsol, Philippines. It is far from perfect, but over the past 5 years it has gone from a free-for-all to something resembling a sustainable operation. Operator cooperation - driven by obvious benefit sharing - was a significant factor in that outcome
Well it's sorta easier for the local community around Donsol to get together on this since they all have a window of a few months to earn and the municipality works together to form the Butanding Festival etc. Plus these whalesharks got a presidential seal of protection back in the 90s (Yea Ramos!). The community was already united in hunting the whalesharks, so working towards sustainable tourism was a matter of fine tuning the process, which they have done very well.
The Maldives is a whole different deal. 6 resorts nearby (if I remember correctly), all international owned by different groups. Then count the liveaboards and other resorts which come from further away, all unrelated to each other and all vying for a piece of the action. Hell I remember reading some sales pitch back in Feb saying to go for the Mantas before legislation is enacted, all for $1500 for 5 days or something. Then you also have the age old locals vs foreigner debate and accusations of vested interest (eg SOS's Guy Steven's is also working @ 4 Seasons and brings tourists out there on his research dhoni. Note this is not saying Guy can't be trusted, even he knows there's such talk) I've seen this happen in quite a few places where there is an international presence (eg Komodo National Park (PNK) when many parties want a piece of the very small pie.
As Guy says, the area is slated to be a UNESCO WHS, which will garner some protection. UNESCO listing can help, as the new restrictions on the tours have had an effect on the tourism and its effects on the wildlife. However, it's not always perfect. For eg, shark fishing can still happen, despite PNG's (or with the help of, if one believes the stories) efforts.