Do you honestly not recognize Sir Patrick Stewart? No shade, it’s just wild to think there would be people who don’t recognize him at all, given the length and breadth of his career.
In answer to your question, I can’t speak for Patric Stewart, but my guess is that he chose to play the scene that way because it’s likely that very few people in the Federation smoke, and that’s probably doubly true for people who spend most of their time on a spaceship. My guess would be that Stewart was trying to indicate to the audience that smoking would be somewhat of an anachronism in the 23rd century.