If you were taking on a raid mob... like a 1min fight, auto attack damage is approximately half of your dps, the other half is CAs. You can see the clear flaw in what they're telling you by that alone.
Them ->

<- You
And if you were to raid in the high end zones, your reduced hit rate would make your dps go down the shitter. Your CAs which hit 99.999% of the time however(in my case anyway), covers your ass in that regard.
Not only that but some of our debuffs help us smack things easier.