insufficient material

I'v had 2 games tied when i had only my king left and my opponent lost on time but the system gave a tie do to "insufficient material". What's the point of the clock if the sys is going to determine the out come like that?

The point of the clock is self-evident. What is missing is your understanding of the rules of chess. To win on time you must have sufficient mating material left on the board.

Your opponent didn't lose on time. Yes, his time ran out, but you had insufficient material to checkmate him. You simply cannot checkmate your opponent with only your king, hence the draw by insufficient material.

And I sincerely hope that you did not question the point of using a clock.