Sure, Saussure has had his share of critics. One reasonably pointed out that not all signifiers have an arbitrary relationship to what they signify—what about paintings and photographs, huh? (Source.)

Poor Saussure has been accused of being a procrastinator, and apparently admitted as much in correspondence with a friend and editor to whom he confessed having a "a morbid horror of the pen." (Source.)

Some critics have claimed that Saussure is not as original as he's cracked up to be. Bummer. (Source.)

Other critics (ahem, Roman Jakobson and Noam Chomsky) suggest that Saussure may have been a little fast and loose with complexities so that he would sound clearer than he really was. (Source.)

This guy was a serious polyglot. By the time he was 15, he could already speak French, German, English, and Latin. He went on to add a few other languages to that list, like Lithuanian and Persian. Seriously, who speaks Sanskrit and Indo-European? (Source.)