Nah... They are not fail...
Jessie and James are merely there to be comic relief, honestly. They make better heroes than villains. I mean, it's easy to tell that they are not the best people that Giovanni has ever hired, because he either always tries to get them out of his sight, becomes highly sarcastic with them, or he just plain dismisses them as much as he can. Just because they can't catch a Pikachu doesn't really reflect too much on the rest of the team.
For instance, look at 009. Domino was pretty awesome, not only could she do amazing stunts but she could fight a Scyther off her with just a stick. She can jump, run, and command very well. She has a head screwed on right. And she admits that Team Rocket agents work in all kinds of places, you just never know. A Team Rocket member could have been following Ash all along and just haven't struck yet, or maybe Ash is just lucky as he infamously is and Team Rocket being infamously unlucky. ((Such as 'blasting off' or Domino falling into the bucket.))
That's what I think. I think Team Rocket is actually really awesome, it's just that many people are tired of seeing Teams, especially Team Rocket, and don't really look for the good in it. Giovanni even hired Hun and Attila, even though they failed at capturing Raikou, it showed them later capturing Rayquaza. I mean, that's pretty good.
My hypothesis is that if you join Team Rocket you're doomed to be jinxed! lol.