Well I really don't know about Burnei, but for Maldives, following might account for it.
Maldives, as we all know, is a group of small (very small) islands with one semi major city which is there capital Male. Most of the Maldivean work for resort companies there or fish. Some might be doing well off jobs but mostly are involved in these two industries. They, in no sense, have a strong or prosperous economy and are only dependent on small resort, fish industry with few manufacturing plants. Due to the remotness of the island, trade basically exists between Sri Lanka and Male. The comments previously posted for this forum says that it will be sensible if SV flies from Colombo to Male. Well, they could take a short, much cheaper route by boats while enjoy the scenery. Besides, Air Lanka flies there and Air Maldives flies to Colombo, so how much market do you think does SV has for their Male route?
For Brunei, I say that SV probably code shares with Some South East carrier like SIA, Garuda and Air Malaysia fly there providing not sufficient market for Brunies.