One thing about football (soccer)

I've wondered for a long time why they don't show the actual game clock that the referee is keeping track of in his pocket to the audience. Why do we still use a straight 90 minute running clock today?

It's obviously not due to lack of technology. I find it annoying that after the 90 minute clock hits 90 nobody knows how much time is left. I think I'd be even more annoyed as a player.

I guess one good thing that might come from it is that only people who really want to win will go 100% after the 90 minute mark. You should be able to see who's really motivated.