You clearly don't understand the changing nature of language. "Great"
can mean "large", but in more common modern American use it tends to
refer to quality rather than size, which is the root of your
confusion.

And your judgment that calling toes "pigglies" makes more sense than a
perfectly valid nonspecific descriptor of its size is puzzling.

The word toilet comes from a word for "cloth" (think of the English
word "towel") and is a reference to cleaning. Over time this word for
cleaning was applied to a modern restroom fixture for collecting
excrement, which sounds reasonable, but this common use gradually
replaced most other uses of the word.

PF