Instead of wasting their potential on variability, they build their character around one powerful tactic. And it works.
Examples are:
bash, bash, flurry
ambush, snare, ambush
neuro, soften, disrupt
quicksand, damaging spells
backstab, cheap shot, parting block
sleep, maledict, wait
entwine, call bloodthirst
stalk, assassinate, vanish
etc etc

None of these tactics work on every enemy, but most people are content with beating 2 out of 3 enemies and just avoiding the rest.
It's CF. If you go for variety, then every single option will be weaker compared to what you might get if you build your character around just one tactic.