If an enemy keeps attacking you (more than once) while you are thinking what will be the best strategy and your party is almost ko'd before you have finaly decided...someone (especially someone new to this kind of play) will start to keep pressing the attack button or overlevel his/hers characters in order to win the hardest enemies.
On the contrary turn based battle,i think encourages the player more to think and to form strategies in order to beat his enemies.

Anyway,both systems have their cons and pros...