I love Sean Carroll (Something Deeply Hidden and From Eternity to Here are the root of my fascination with physics and endless pondering of the nature of time) but I have to disagree with his take on this.

Hypothesis - a proposed explanation for something (such as a phenomenon of unknown cause) that is tentatively assumed in order to test whether it agrees with facts that are known or can be determined.

Theory - a scientifically acceptable or plausible general principle or body of principles based on data and offered to explain phenomena

Just because those outside of scientific fields use them interchangeably doesn't change the fact that they carry different meanings in scientific contexts.

It seems to relate much more to the size of the proposal than to its confidence.

Even more because the confidence changes all the time, but people do go around renaming well known ideas