Here's a good long article about the topic from 2010 and recently updated 2019: https://www.seriouseats.com/2010/12/...-is-not-u.html
An excerpt close to the end - "In large part, it's because foie gras is an easy target. There are only three foie farms in the country, and none of them have the money or government clout to defend themselves the way that the chicken or beef industry does. It's a food product that is marketed directly at the affluent, and the rich are always an easy target. As an occasional delicacy, it's also a food that's relatively easy for most people to give up.
Personally, I find this kind of protesting abhorrent. If you are going to protest anything, it should be the industrial production of eggs, through which chickens are routinely kept in cages so small that they can't even turn around for an entire year. The problem, of course, is that you tell people to stop eating cheap eggs, and nobody will listen. The leaders of the anti-foie movement know this and use it to their advantage, using video and photographs taken from the worst of the farms (none of the ones in this country, for the record), and making it seem like all foie production is as despicable."