[intergalplan]

A really good point, and all the more reason to make developer-visible async behavior something the developer has to to ask for, even if the call is in fact async under the hood and might let, say, code handling another request run while it's waiting on I/O.

I think a pattern where there are one or two great places at the lowest level of a Node program for program flow to act async, and then a bunch of business logic where it rarely is (probably running "under" the part where async makes sense, if you take my meaning) is far more common than those where async-friendly flow is what you want for over 50% of calls. "Call this chunk of code async, but run everything in it exactly in order" is super-common, and the interface to achieve that is exactly backwards in Node.