Some people take longer to grow up than others. If you love knitting then just ignore, their stupidity. Just remember those that make fun of you later on . Those are the one's that won't get one of your awesome hand knitted projects , that others are asking for.
Like felted clogs! my friends made fun of them while I was making them ,until the saw my finished clogs. The one's that laughed and made fun of me ,will never know how wonderful these clogs are.
By the way, knitting is not an age or gender thing. I only wish I had started when I was younger, I started at age 53 and I'm 56 now ,I can't believe that I wasted all those years not knitting.
There are so many crafts and arts that are being lost to the youth of today, I love seeing younger people bringing it back into style.