If anything, I say thats a rather good tank for a pet store.
Ok, before all you you think I have gone mad, let me explain myself.
The crabs that are in there only wears natural shells and has more natural shells to offer. I never really seen a store that doesn't have at least 10 crabs without painted shells. But maybe the painted shell fad isn't really "popular" in Singapore? If there was water in the water dishes, they would make the ideal water dish as they look pretty deep.
It is very common for a pet store to provide only commercial food, after all thats what they would stock and they can use it for a discount instead of paying money to get natural foods. While looking at the ingredients, I didn't really observe anything alarming and think that would be a pretty good food mix to feed your crabbies if you going away on holiday - for example.
The sand base is deeper than most pet store i ever seen! This is great for the hermies that want to dig down a bit and just chill without them moulting in the tank - as it looks to me that they could dig down but still not far enough where they would be lost forever.
Personally, I think all they really need to work on is getting the heat and humidity up to par - as
Crabbzymagnus said it is a shopping centre so it probably would be air conditioned - and actually getting some water into those water bowls.

It is certainly better than most shops - ok, I lied all - in Melbourne... Well, that I been to.