just curious, but when was the last time u won a game turreting frostbolts, you had no ice block and still survived survived with 200 health cause ur barrier absorbed 200 extra damage, or u ran oom? (all the benefits of running int over mastery)
now think about the last time that healer got away with 100 health?
the thing is tho .. turreting frostbolts gives you chances to proc FoF / brain freeze for even more damage .. i dont know how many games ive won with a frostbolt shatter - a good base intellect with a solid mastery is absolutely incredible i personally like gemming full intellect and reforging mastery .. you wouldnt crit as high as me if you just gemmed mastery yes you would hurt but you wouldnt nearly do as much damage as a intellect mage with mastery reforged.
i know some mages that are int+mastery gemmed with a couple int gems here and there and are sitting at 8900 spell power something in the ball park of 9100 with intellect ( my math is off i know) mean while the int mage is sitting close to 9800 and with int up i have 10.1k spell power .. reforged mastery i have 32% roughly for extra shatter damage and ive been playing around with foul gift which increase your mastery it leads to some killer killer shatters
i kind of feel like its the same argument that mages had at the start of cata with Crit and mastery .. sure you crit 90% of the time but your shatters didnt really do anything without mastery .. some mages do really well with one stat while others do well with another i feel it REALLY comes down to playstyle not every mage plays the same - some really rely on the whole ice lance and win tactic while others rely on deeping their kill target into a shatter