''In the sense that burning methane is easy, but making anything out of methane is difficult.''
Well yes sort of.
This is my simplistic take on it. Someone more familiar with astrobiology please correct me if I have got it wrong.
What is Consuming Hydrogen and Acetylene* on Titan?
*Acetylene properly known as ethyne.
http://www.nasa.gov/topics/solarsystem/features/titan20100603.html
At the surface: Hydrogen + ethyne/ethene = Methane + energy (bond making exothermic)
At higher levels in the atmosphere
Methane + energy = hydrogen + ethyne/ethene (bond breaking endothermic requiring energy input)
Where might the energy come from? Photolysis i.e., the sun.
The article says this:
"It's as if you have a hose and you're squirting hydrogen onto the ground, but it's disappearing," Strobel said. "I didn't expect this result, because molecular hydrogen is extremely chemically inert in the atmosphere, very light and buoyant. It should 'float' to the top of the atmosphere and escape."
And from this article; Have We Discovered Evidence For Life On Titan
http://www.spacedaily.com/reports/Have_We_Discovered_Evidence_For_Life_On_Titan_999.html
‘’ McKay and Smith (2005) predicted that if there were life on Titan living in liquid methane then that life should be widespread on the surface because liquid methane is widespread on the surface. We have direct evidence that the surface of Titan at the landing site of the Huygens Probe near the equator was moist with methane, and radar and near-infrared imagery from Cassini have revealed extensive polar lakes on Titan, both north and south. Methane-based life would have a lot of environments in which to live.’’
Now to return to the OP’s original point – the sun is the source of life. We can worship it much like the sun worshippers of Egypt and Canaan etc. (http://www.sacred-texts.com/astro/slaa/slaa08.htm). Or we can take things one step further back along the chain and ponder what created this, if you will, energy inputting, entropy defying and arrow of time source of life?
In the beginning, God created the heavens and the earth. The earth was without form and void, and darkness was over the face of the deep. And the Spirit of God was hovering over the face of the waters. And God said, “Let there be light,” and there was light.
OK I know we are never going to all agree on the last bit, but I thought that I should attempt to respond to the OP's original very interesting question.