How much do I like APIs? A decent amount, it seems. They keep me employed, to an extent, and they make it pretty seamless for me to check the weather, my email, the stock market, along with a thousand other daily use cases. They justified my work paying for me to fly to Melbourne for two days to attend a conference about them.
I don't just like APIs because of the free food and chance to spend time in airports and around lakes. I like APIs because, I think, they're just my kind of software.
Two aspects of my personality are solved by good APIs.
One, prescribed, effective communication. APIs have standard protocols and mediums. Connecting to one can be done at any time. Responses contain the data you asked for in the format you expect. There's no standing around with a half eaten pastry wondering if you should speak now. No waving back at someone who was actually waving at the person behind you. No lingering once the message has been delivered. Good APIs are elegant and clear.
Two, APIs enable maximum efficiency for tiny increases in value. You can asynchronously plug in to an operation while the main program carries on. I prep my milk and take my fish oil while I'm cleaning the blender each morning. If the interfaces of the froth button and my mouth weren't always available I'd spend more time each morning achieving the same result. APIs let me upload images while I'm creating the entry, and spam new iServer objects via a script instead of using the UI.
So yeah, I do like APIs. And free food. And even kinda airports.