Sanchez has had immense pressure from day 1- trading picks and players to get him, starting from day 1 w/ a coahc talking championships, starting on the road in 6 playoff games.
Matt Moore has no pressure to win right now which is why he is thriving.
These are just bad excuses for your mediocre QB. Matt Moore doesn't go into a football game thinking "Oh, we are only 3-7 I guess I'll just play awesome." And if Sanchez is thinking "Oh my gawd everybody is expecting me to succeed!" then he really shouldn't be the leader of the team or the QB. Every QB has pressure but if it effects them so bad it's going to effect their play then their not a good QB.