I think probably every prognosticator was called a chicken little, and every warning of a slippery slope ignored until there was a pile at the bottom of the slope and no one knowing how they got there.
I see slippery slope warnings dismissed all the time, especially here, as naïve and folly. Not very many significant changes in human society have happened in one fell swoop. It is gradual. I think that is good for society. Many argue that Roe v Wade got ahead of a trend already underway in our society, and is why it is still controversial today. An evolutionary process was, well, aborted, by the Supreme Court. But, the slippery slope is also bad for society. A change can occur so slowing and covertly that it goes unnoticed by the masses busy paying a mortgage and finding a good preschool. When the change is slow and minute, even petty without context, it is easy for people desiring the change to divert attention from what is the end state. To dismiss the slippery slope is myopic and unwise.