I've done it both ways. To be honest I feel like the team sets the tone. If you are in a team that has quite diverse ability (amazing to competent) I find that sometimes the better players get frustrated very quickly when the team starts to go go down. Rather than try and work out why everyone is dying or what the weak link doesn't understand, they get angry and start telling everyone to do their jobs! This leads the worse players to feel more incompetent and they invariably play worse. Then the cries for using the exploits grow louder and you just have to go along with the team or start again fresh.