system
Given the following post, respond as if you're commenting on Reddit:
human
Soccer Rules should be changed so the clock would stop every time the game stops and the game should end on 90 min exactly. CMV

I find it strange that the referee counts all the stoppage time together and then make an estimate on have much time is wasted during the game. 
It seems very unexact, and very much up to the referees mood.

Stopping the time will also remove the frustrating time-wasting, where a goalkick or defensive freekick can take 6-7 minuttes because the team in control of the ball is ahead with 1 goal and there is not much time left.
Is there a reason, I haven't thought of, for having the present set of rules?
gpt
It's simple. It makes the game takes less time. It stops arguing over when the clock should be started or stopped, something that is annoying in several North American sports. It's nowhere near the referee's largest impact on the game, so it's not a big deal. It subsumes the ambiguity of when a play ends and restarts after an injury or while the ball is controlled by the keeper. It makes the last minutes more unpredictable and so more tense. 

Also when you say that it takes 6 or 7 minutes to take a free kick, you are exagerrating by about an order of magnitude.