Because everybody gathering round the referee or walking off to chat to the manager and grab a drink doesn't 'hamper the flow of the game', right? Surely the tech comes into play when the ball goes out, rather than interrupting the game, it's not a difficult concept.
There's no point arguing with you, you've obviously decided on your opinion and won't budge. Doesn't make a difference. Goal line technology has been a success; the refereeing this season has been a shambles almost unanimously. The combination of these two means there will be more technology coming into the game, no doubt about it.