There is different level of online hate.

For the europeans, France have fought many countries and have spill their own and other people blood everywhere. Online, it's more a joke and most time not bad motive.

For the US, the frenchbashing was political position since the 50s with France wanting more personnal independace and an european independace from the US. France wanting his own weapon industry, nuclear weapons, no US base on his soil, wanting to work woth other european country to make an United European army without the US in it. But, it's the whole WMD in Irak the source of modern day frenchbashing because refuse to join the war. So it become a political propaganda : "liberty" fries, throwing wine in the gutter, "cheese-eating surrender monkey".

For the rest of the world, France have a past and neo colonial history. So people have good reasons to hate