I think he was saying (at least in the last line of his post) that mages with subpar gear go arcane because arcane has talents that increase your spelldamage  by a percent of your int (like 15% of your total int) so they stack int which is easier to do with some gear and then take other talents to increase their int too.  It's a symbiotic type of circle of life relationship.  And yeah, I think you do get a very small amount of crit per int too as a side bonus.