Why aren't positive and negative charges attracted to each other?
They are, it's an external force that separates the charges into a dipole. If you apply a sufficietly strong uniform external field to the charges, the positive charges will want to go one way in the field, the negative charges will want to go the opposite ditection. Your external field overcomes the field of attraction between the charges.
"Charge" does not exist by itself, bodies can be charged. Think you have two beads made of some plastic, and give positive charge to one and negative to the other. The beads will attract each other and stick together at the end. Their charges can not wholly neutralize as the beads do not conduct electricity. One side of this "dipole" is positive, the other is negative.