I believe it changed due to the change of culture in the era. When you look at modern architecture it looks totaly different from 40 some years ago. Because of this change in the architecture, since most likely it was the culture change it was significant to the eyes of the church-goer of the time because no one has seen anything like it.
When referring to it in Architectural terms only the creature serving as actual water spout is called a Gargoyle, otherwise is it known as a Grotesque.
