In recent years, especially those surrounding the Iraq war around 2003 or so when they refused to help us in the crusade, Americans have become more anti-France after them being our friends for much of our nation's history. Likewise there has been a slight stigma toward those whose foreign language of choice is French or are interested in French culture, as this blogger mentions.
I have found this francophobia largely comes from a particular generation of Americans, the one now at the middle of its life: Generation X. (Of course this and other points mentioned here are a generalization; no offense to any Xers who are francophiles instead.) Why is that? Well, a lot of things modern France is known for runs counter to the philosophy of an average Xer - such as being too "socialist" and an example of why "New Urbanism" (which many Millennials are embracing) is a much more environmentally friendly way of living as compared to the sprawl typical in America. By the way, except for possibly the "old-old" GIs, Xers are in general probably the least environmentally-friendly generation alive today (especially when it comes to regulations on business) - the last one to embrace the consumerism and car culture typical of Americans in the past saeculum (and actually turned back the progress Boomers made towards a "greener" lifestyle - one that Millennials are reviving).
An outiler to this (ironic considering they're the ones typically blamed for the decline in the interest of the French language in America) are Latinos (which as I've said the first-generation ones in America are most concentrated among Xers). In fact, as some bilingual English-Spanish families such as one from this site have done with their children, when a third language is studied guess which one they're most likely to go for? You guessed it, French (which for those who already know English and Spanish is a relatively easy step, and those three languages together will allow you to get around a significant part of the world).
So which language do I think is French's biggest "enemy" in the language-to-study-war? It's the language of an Asian country that is quickly becoming more like America in the way a lot of pro-suburbia, anti-environmental people like (and if that group wins then life on this planet may cease to exist in a few decades). The country is China, and the language is Mandarin Chinese. I had originally planned to do a blog post on that language, but since that fell by the wayside I'll touch on it here.
Xers are probably the generation that has done the most promotion of the study of Mandarin, citing that there are more speakers of it than any other language in the world, that China is quickly becoming a superpower, and that the language may be the new "global" one in a few decades like English is now. The opposition (which I side with) cites that the importance of Chinese is overemphasized since its complexity compared to most "Western" languages means it's unlikely to attain importance at a global level, and unlike for example English, French, or Spanish which are spoken in multiple countries across multiple continents the only place Chinese is spoken as a "primary" language is in China (apart from "Chinatowns" around the world). (Not that I have anything against Chinese people or their culture, but like many Millennials Chinese political ideals run counter to what we want and that although studying Mandarin is a worthy venture it's not necessarily THE language you should study. Another reason not to go that route is that it takes on average A LOT more study to achieve a comparable fluency in Mandarin than it does with languages more closely related to English, unless you already know another Asian language.)