A stupid play will NOT effect the players results. But it will effect their manners.People often get irrational when you make a play they don't approve of.Times like that,its good to have a large cheap cigar in your pocket.Look them in the eye and say"Well,if you didn't like that,I'm sure you will just love this" as you light it up.Works even better if you are hitting a soft 17 at the time.
Bottom line-play the best game you are capable of,and don't worry about the rest of the table. The good players know better,and the jerks will be jerks,regardless.