Arguing that its easy to sunder means that sunder should be a standard action is not valid. Tripping is probably easier than sundering but yet you can trip 5 times a round if you have enough attacks and enough opponents to trip. The mechanics of sunder may be poor for attacking attended objects but that is bad design.
Also read sunder over and over and over. See that it is an attack directed at a weapon/shield/object and does not warrent the need for footnote 7 because it is not a substitute for an attack, compare it to trip and disarm. Disarm says "As a melee attack..." trip says "you make attempt to trip an opponent as an unarmed melee attack...". Sunder "you can USE a melee attack...". Similar but different, the wording for trip/disarm are meant to show substitution using the word as while sunder is meant to show it is a melee attack. On top of that the rest of the actions on the standard action part of the chart say that it requires a standard action to perform in their description where as sunder does not, it only mentions an attack.
Also, see that on the actions in combat chart it is Sunder a Weapon (attack) not just Sunder. indicating that it is an attack.
Look at the special attacks table it says that you strike a weapon, and I don't know any other way to strike anything other than making a melee attack against it (or some magic); which is what sunder says you do.
To Hypersmurf: Your argument that you would allow a sunder as an AoO if the weapon/shield provoked would only work if you also would only allow disarm the same way. Why would a kobold provoking at AoO by moving be subject to disarm, it wouldnt with your logic (and if you change it in your game more power to you). But it is allowed in the rules.
Patron: You can shocking grasp as a AoO if you have the charge ready, since having an offensive spell charge held counts as being armed. However you cannot cast a spell as part of an AoO because casting a spell is not an attack and is specifically stated as a standard action. The sunder description says it is an attack, thus you can sunder as an AoO. Again I refer you back to the description of sunder, " You can use a melee attack...". A single melee attack.
Also, you cannot take a full attack on an AoO because it is not a melee attack is it multiple melee attacks, which is covered under the AoO description.
Also read sunder over and over and over. See that it is an attack directed at a weapon/shield/object and does not warrent the need for footnote 7 because it is not a substitute for an attack, compare it to trip and disarm. Disarm says "As a melee attack..." trip says "you make attempt to trip an opponent as an unarmed melee attack...". Sunder "you can USE a melee attack...". Similar but different, the wording for trip/disarm are meant to show substitution using the word as while sunder is meant to show it is a melee attack. On top of that the rest of the actions on the standard action part of the chart say that it requires a standard action to perform in their description where as sunder does not, it only mentions an attack.
Also, see that on the actions in combat chart it is Sunder a Weapon (attack) not just Sunder. indicating that it is an attack.
Look at the special attacks table it says that you strike a weapon, and I don't know any other way to strike anything other than making a melee attack against it (or some magic); which is what sunder says you do.
To Hypersmurf: Your argument that you would allow a sunder as an AoO if the weapon/shield provoked would only work if you also would only allow disarm the same way. Why would a kobold provoking at AoO by moving be subject to disarm, it wouldnt with your logic (and if you change it in your game more power to you). But it is allowed in the rules.
Patron: You can shocking grasp as a AoO if you have the charge ready, since having an offensive spell charge held counts as being armed. However you cannot cast a spell as part of an AoO because casting a spell is not an attack and is specifically stated as a standard action. The sunder description says it is an attack, thus you can sunder as an AoO. Again I refer you back to the description of sunder, " You can use a melee attack...". A single melee attack.
Also, you cannot take a full attack on an AoO because it is not a melee attack is it multiple melee attacks, which is covered under the AoO description.