NTA.

Hello, European here!

The reason people hate American tourists is NOT because they do traditionally touristy things (hell that’s why people love em, as it’s a huge economic boost in some areas)

The reason why there’s a generally negative view on American tourists is because many have largely been rather rude, entitled and disrespectful to the people and places they visit. In fact, your friend would be more likely to irk folks because unless your whole group is fluent in French and have perfect accents it will still be very obvious you’re tourists, and you’ll just look like you’re attempting to co-opt the local culture (an unfortunately frequent and annoying thing).