For the most part, it's not a problem. We are taking about 5% of the community here. For the most part if somebody doesn't want to play, they go to orbit at spawn, or they come in about half way through the first wave battle, and then play for the rest of the strike. Sadly your best option is to report them as being unhelpful. If enough players report someone for being unhelpful, eventually Bungie will investigate and slap them with a temporary ban.