Whether it is a run and gun shooter, a vehicle based shooter or real time strategy, fast reaction times are important, even if there can be a lot of strategy in choosing weapons or when to activate abilities.
I'm not very good at such games, so I've had a few ideas of slower paced games. I think they main concern is making it as exciting to watch as it would be for the players. People do watch chess tournaments, but even those have timers.
Time limits could be much shorter in a game, and still provide plenty of time to react and make tactical decisions, but that would depend on game mechanics.
