i expect that most people who say "that sounds like fruity" either recognize a preset, or are really meaning "that sounds like somebody without much experience".
That's simple to fix, though; just junk all the synths that come with FL and get used by everyone and their dog, and the "gimmicky" effects, like wavetraveller, then feed it new plugs and hook it up to external gear and your own samples. As if it's going to sound like anything but "you" after that...