I think everyone has a pet hate when it comes to phrases like "to be honest".
This is my favourite pet hate (oxymoron/paradox - no, seriously, I don't know)
The obvious implication of "to be honest" is that the speaker has not been honest previously, or if they do not prefix any further statements with "to be honest", those statements too may be suspect.
I was going to say that "frank" would be a better word but a look at the online Oxford Compact English Dictionary has a definition as "honest or direct" which sort of messed me up but I will plow on nonetheless (albeit briefly - I don't want to risk my reader - me - getting bored) ....
The phrase is symptomatic of people not have a good enough command of english and thus using it as a conjunction, or to fill in a blank while their mind catches up with their mouth.
Now I'm going to consciously listen for good examples of this, and other well worn phrases and, mixed metaphors - I love mixed metaphors!
