He is too tall.  Brad Butler measured in at 6 feet and 7 1/8 inches at the combine.  His listed height is not an exageration.

Picture a center, bent over before a snap.  Now imagine how much time he has to give the QB the ball, stand up and drive his body forward before the DT gets his hands on him.  It happens so quickly that every inch is crucial to establishing leverage and getting the proper hand placement to control the DT.

Here is a list of every center who started 5 or more games last season and their height:

Eugene Amano - 6'3
Matt Birk - 6'4
Jeff Faine - 6'3
Mike Flynn - 6'3
Melvin Fowler - 6'3
Hank Fraley - 6'2
Eric Ghiaciuc - 6'4
Andre Gurode - 6'4
Rex Hadnot - 6'2
Nick Hardwick - 6'4
Eric Heitmann - 6'3
Jamal Jackson - 6'4
Al Johnson - 6'5
Ryan Kalil - 6'2
Dan Koppen - 6'2
Olin Kruetz - 6'2
Sean Mahan - 6'3
Nick Mangold - 6'4
Kevin Mawae - 6'4
Todd Mclure - 6'1
Andy McCullom - 6'4
Brad Meester - 6'3
Tom Nalen - 6'3
Jeremy Newberry - 6'5
Dennis Norman - 6'5
Shaun O'Hara - 6'3
Casey Rabach - 6'4
Dominic Raiola - 6'1
Brett Romberg - 6'2
Samson Satele - 6'3
Jeff Saturday - 6'2
Chris Spencer - 6'3
John Wade - 6'5
Scott Wells - 6'2
Casey Weigman - 6'2
Damian Woody - 6'3

To summarize there are:
6'5 - 4 players
6'4 - 9 players
6'3 - 12 players
6'2 - 9 players
6'1 - 2 players

There is some obvious symmetry to the list and it is apparent what the ideal height range for a center is.