Archaic racially-charged pejorative epithets (like the 'n' word) are rarely seen today, but are still occasionally seen in the speech of the older generation (who are resistant to change)
Damp spoon syndrome - stems from the distasteful act of leaving a damp spoon in a bowl of sugar, implying that people are lazy and disrespectful of language
Infectious disease assumption - changes are like germs which spread and infect the language
Crumbling castle view - English was at some point at a 'golden age' and is now in a state of disrepair
Accounts for errors - when someone makes an error (a 'random fluctuation' in the standard), these errors can be standardised and recognised as somewhat synonymous