actually no, you're wrong, infernape is known to create switches so you'll have plenty of oppurtunities.
eg:
-blissey switches out(to avoid close combat) and kingdra switches in.
-infernape uses nasty plot. infernape's sp.att sharply rose
of course it's not that simple either. the opponent could counter with a fast pokemon like starmie instead of kingdra so it may be smarter to use grass knot instead of nasty plot. then again, if your foe is familiar with your style it'll leave blissey in to take grass knot and use twave to render infernape useless. so really, nothing is that simple, but pulling off nasty plot is quite easy.