No good deed goes unpunished. And in this case, the deeds often aren't even good. Locals from Ghana to Bangladesh complain about how China brings in their own workers rather than employ locals, and how the end result is shoddy work and more money in the pocket of corrupt officials.

Now it may buy influence from the goverment, but as I mentioned, governments are fickle things and power changes hands frequently.

All the same, I don't think this is irrational behavior from China -- they need to win friends and influence people.

> And when did a Blue Water Navy become cheap?

You'd have to compare the payback period for investing in slum upgrades in Indonesia vs investing in one's own Navy. In many cases it's never vs some intangible number of years.