Crit loss is mostly because of eye gems. Mages with imbued set filled with full eye gems could reach very high % of critical especially if set was tactic. Now you Also can reach good crit but it will cost you huge damage, HP or both loss. We got jewels now to get stat we wish. It's not same as eye gem but now at least its mostly affordable to all players.
Rogues can one shot but they Also can be one shotted. Mage always have spot in PvP and always had. It wont change. With or without speed set mages are powerful class especially in clashes. Speed will cost you stat, choose is up to players to use it or not.