Most people are trying to get through as quick as possible, which is understandable. If you'd like to take your time dealing with every enemy you should probably continue doing patrol missions. At any rate, if choose to chase every enemy that's up to you, but if your team is pushing ahead you are being just as "unhelpful" for them. I like to push up, I'll take must of the enemies out along the way-but if someone is spending 5 - 10 minutes on enemies outside the path of the mission.. well don't blame people for leaving you.