But you have said for a long time they are the worst civ because you cannot harvest resources.
You will not get nan Madol every game.
The yields of harvesting resources is reduced in the September patch.
If you don't have Nan Madol, invest on Kumasi.
If you don't have Nan Madol and Kumasi, invest on GP +% culture CS.
There's always someone worth investment if you meet all of the CSs early.
There's always some yieldful wonders on the map, but if you're not Maori you may not be able to settle there easily.
I play continents, exploration is xtremely important on continents.
What is called "useless exploration"? You give up building a builder or settler to build a scout, but that scout moves slowly in forests and finally being shot out by a barbarian archer. (or skirmisher/xbow)
What is called "exploration"? You explore all over the map with Maori's +2 movement, in ocean there's no barbarian at least in early game. You meet all Civs (that is not useful), all CSs close to coast, and collect all tribal villages. (especially those island or polar ones) You explore all coastal wonders.
Exploration is really important, but unsafe exploration by a 10-strength scout is not real exploration.