Is that correct, or are they misinformed? If I recall correctly, there was some kind of dictatorship in Elsweyr before the Empire took control, and things got better after Tiber's conquest. I'm not that knowledgeable about Argonia's history, though.
So, when Tiber Septim conquered Elsweyr and Argonia, did the people of these provinces get it better or worse? Did they become opressed (or more opressed)?
PS. I've also seen someone state that he hated the Empire because they enslaved the beast folks, but I know I'm right when I say that's false, considering that the Empire frowns at slavery. The only time the Empire could've used beast slaves must have been at the time that they also used man and mer slaves.