The terrain at Bacalar Chico is Mangrove lagoon and Littoral (flooded)forest and the ruins are scant and not the stone temple/pyramids like the mainland and rain-forest.
It's hot mosquito infested and hard to get to.
Your sensing lack of enthusiasm, yes, and I'm guessing your imagining a trip much different than what you'll get.
Try Lamani, an amazing rainforest hike with tall stone Mayan ruins.
On the islands what we call Mayan Ruins are usually black dirt rising in the swamp however I see some stone at Bacalar but just a little.