Turn based tactical games can be played at ones own pace, play it when your waiting for some one, while you commit, when you can't sleep, to relax, beat yourself specially when it has a score system with turn counts (damaged units, enemy units destroyed, etc...).
Turn based makes you more in control and more organized, focus on positioning. Its easier to understand every detail and effects of each individual units, weapons, skills, powers, etc... And sometimes control your opponent to do exactly the moves you want. What a rush when that happens.
I think a real time system is more about strategy, the abstraction and chaotic and luck that it all works out. Turn based is about tactics, detail, controlling the luck factor.