That's the canonical use case, I have seen a few others. Obviously storing passwords in the clear is bad, mmmkay. Mostly it's done as a concession to getting started quickly slash working out of the box, and users are admonished to set the password some other way for production use. The key point I want to get across here is that users want either attribute-like behavior, or they want persistent per-node data, but very rarely do they want both. The rare cases where both behaviors are desired can be reimplemented by copying persistent data to a non-persisent attribute in cookbook code.