Is the "Uber for X" snowclone nominative fair use?

That's the question posed by the following ad (HT Zach Schrag):

"Turo is like Airbnb, but for real people's cars" -- USA Today, quoted in ad for Turo

This snowclone is common in (often mocking) descriptions of Silicon Valley elevator pitches, but what about use in an actual ad?  Does it matter that Airbnb may well have aspirations to be "Airbnb for cars" itself if the business model is viable, just as Uber desires to expand into different market niches?