But doesn't floating mean they're open to air? That can let mold or bad stuff grow on top. I've ruined whole jars when my pickles didn't stay under the brine. Using weights just makes sure they're fully covered and fine. Yours might taste okay now, but why take the chance?
Isn't the acidity what really keeps them safe though? I've had pickles float for months and they taste great, no mold. Weights just add extra stuff to clean and aren't always needed.