Well, no, at 11 months it isn't necessary
But... people feed their 11 month old babies jars of food, or mashed up food, and that's generally considered fine. I didn't do it, my babies have just been given whatever's going - but loads of people do.
So, even though its unnecessary, its no worse or different to giving mashed or jarred food really (as long as the chewer is healthy). The disease thing is a red herring IMO - BF carries transmission risks but only in certain circumstances and we don't have a thread going ohmigodhowunhygienic every time a sleb BFs in public 
Each to their own and all that [shrug]
I bet the penguins would use a blender if they had the chance btw. Who wants to vom up raw fish?