Imagine, for an instant (trying not to poll jump, this is just one of infinity possible outcomes):
CaP9 @ Choice Scarf
Type: Dark/Fighting
Ability: Klutz
Stats: high Atk, Spe, moderate-good Defenses, about zero SpA
Nature/EVs: +Spe Nature, max Atk + Spe
Pursuit
Close Combat
Trick
Taunt (or new Taunt-like field effect move)/ Rapid Spin/ Aromatherapy
Scenario: Common Trickster comes in, goes for the Trick. You send in CaP9 and they trade Scarves, so they have to switch or whatever. You get the easy Pursuit (hits most common Tricksters SE) AND can Trick your own Scarf away from there and otherwise shuffle items around the opposing team without caring what they are. Fourth move helps with another class of secondary moves you want to "stop."
How does this pokemon stop Trick? That part should be obvious. How does it stop other status? Speedy Taunts, Aromatherapy, ability to Trick Scarf ANYTIME. Rapid Spin could stop entry hazards (what ghost will want to switch-in here besides Scarf Gengar with the risky Focus Blast?), or Aromatherapy could heal CaP9 and its teammates from status (whichever benefits your team more), all the while being a strong physical threat.
Basically what I'm trying to say is Klutz is a great ability to have on a "Stop the Secondary" pokemon.
You forgot that if the pokemon being Pursuited switches, you can change moves. So you can forgo Klutz.












