Sometimes that's not enough. All I'm saying is that switching out is necessary, or at least will be at some point. Whenever I face a fire team with my grass team, I know I have to keep Shiftry and his Earthquake alive and juggle it around constantly. All of my pokemon on my grass team have at least two attacks, but Shiftry does the best job at sweeping those kinds of teams and I'm more than willing to let Ferrothorn go down to let Shiftry switch out and in for the fresh Fake Out. It's a valid strategy, there's a reason you're allowed to do it.
Actually, it's all part of the strategy. I find that when I do switch a lot, I win most of the time. I'm trying to get used to switching more. A lot of the time, the opponent is trying to get rid of one of your pokemon so that their main sweeper can sweep. If you keep that one pokemon in and it faints because of it, you'll quickly find yourself getting swept.