As I mentioned on another post, I remember Ernie Machin sitting on the bench puffing away after being substituted...it was all perfectly normal then. So long as you did your job on the field, that was all that mattered...Wilshire isn't doing a bad job so what's the problem? And I speak as a non-smoker!
Sport science has moved on massively, and each player represents a significant investment especially at higher levels. Wilshere may not be doing a bad job, but if he's willfully doing something that could impede him in any way (even if it's a crafty fag or sneaking some ketchup) he'll be criticised. As lucrative and cushy as it appears, being a successful footballer does involve a lot of sacrifice. I admire the players who get fat when they retire, making up for lost time.