Go ahead and set your two terabyte database to autogrow by 10% and enjoy the wonderful performance this video suggests (as you look for a new job)...I dare you.
Or do something sane and calculate the maximum amount of wait time your users are willing to tolerate, determine the amount of space Sql Server can initialize in that time, and set the value appropriately.
Oh Mark, If it is situation of 2 TB size database, that would be probably partitionated on 5-10 HDD... I think that Brian stated that it depends on the case, and the 10% was just an example. Man should think a little bit before. If I have a database with grow of 5-7% I´ll put 10%, but if it is much less, maybe is better to do that manually.
Planing is also important.