Smurf continuity is rather fragmented, but one thing is certain - Smurfette was originally created by Gargamel as an artificial smurf, and introduced to the smurf community to cause havoc, and she was made into a "real" smurf by Papa's magic.

Now, there were various other females inserted into continuity after the fact, but at the time - to my understanding of Smurf lore - she was the lone lady. This makes sense when you consider her name - all other smurfs are named only for their distinguishing characteristic, and Smurfette's distinguishing characteristic, apparently, was that she was a female version of a smurf.

So, before Smurfette was introduced by Gargamel, if there were no females, were the smurfs truly male? After she was introduced, were they more male than they had been previously? If Gargamel had instead sent out a Smurforio, an artificial smurf with exaggerated masculine characteristics, compared to whom the natural smurfs would appear less male, would they then be female?

Or, alternately, imagine that humanity encounters a hermaphroditic alien race, and we attempt to integrate them into our society. Would they feel pressured, you think, to adopt either a masculine or a feminine aspect, to choose a pronoun, either collectively or individually? If they were all shorter and willowier and curvier than humans, would we instinctively think of them as female? And, if they were, collectively, more exaggeratedly feminine than our actual females, would we come to think of human women as an inbetween gender? Conversely, if they were taller and blockier than humans, would we instinctively think of them as male, and come to think of human males as the inbetween ones?