There are maybe five American posters on this forum that I'd describe as socialists, and that includes democratic socialists like Madeline and revolutionary socialists like myself. A lot of people wearing the avatar are boiler-plate liberal Democrats, yes. But that's what happens in a country where 'socialism' is alternatively defined as 'anything the government does' (literally a libertarian definition of what socialism is) and/or 'SWEDEN' (which is not socialist and never has been socialist, because social democracy is not socialism)
Even though you just included Social Democrats in your counting of the legitimate socialist avatars
No I didn't. Democratic socialism =/= social democracy. The former is interested in changing society (albeit through piecemeal, parliamentary reform), while the latter is interested in making a few changes here or there, but not fundamentally altering the capitalist system.