Well, I had the same question and I came here to search for the answer.
I am going to finish my basement and the bathroom will be really close to my furnaces. So I too thought to myself, I wonder if I could run the bathroom vent into the furnace exhaust vent that goes from the basement up to the roof.
So I don't think it was a stupid question.
There are no stupid questions. The fact that you took the time to ask speaks volumes. Many people that do have the knowledge and years in the trade sometimes forget what it's like to not know certain things, and forget that they haven't always known what they know. Some of these same people also think they know it all, but never stopped to ask these "stupid questions", and in reality only know enough to be dangerous because they overestimate their knowledge.