Here's something else I found on why French = frogs. The one I previously posted was from what I had heard (and its still true we eat em lol) but this is another explanation I tried translating from another website which only applies to Quebec since it isnt linked to France in any way in this explanation.
The origin of this name comes from an old political and linguistic conflict between french canadians and the english canadians. The English Canadians lent the nickname of "Frog" to the French Canadians (who also used the term "French frog"), because this species are subjected to living in the hollows. Such were the maintained thoughts, at the time, by the English Canadians towards the French Canadians. At the beginning of the 20th century, at the time of the period of industrialisation and urbanisation, several country inhabitants of Quebec left their grounds in order to install themselves in the United States and to work in factories for anglophone employers because of a famine that happened here at that time (mentioned here, same thing that happened in Ireland but less catastrophic http://members.tripod.com/gail25/que4.htm
). These employers benefitted from this not very costy 'main-d'oeuvre' to reinflate their trade. Some (employers) even established themselves in Quebec. These English criticized the political and linguistic system French-speaking Inhabitants of Quebec. Consequently, a fight was carried out by the Inhabitants of Quebec to preserve their policy just as their language whose reputation was very negative. Indeed, French inhabitant of Quebec of that time (the joual) was regarded as a symbol of misery and was seen like a defective or retarded way of expressing yourself. The feelings of inferiority, of domination, of incomprehension just as the fear of assimilation dug a large gap between the two people. This national fight gave place to linguistic quarrels during which several launched insults at one another. The French Canadians were called names such as "Frog", "French pea soup", "Pepsi", "White Negro", "Cannuck", "White trash" whereas the English Canadians were called the "Square Heads" and the "Damn English". Today still, the tourists inhabitants of Quebec on the beaches of Florida are called "Frogs" by Floridians. However, since the inhabitants of Quebec have a propensity with humor, they can laugh at this small historical nickname.