Most people know how bad they are and don't like to be reminded, cause they may feel like they are trying their best to do or be better, and being reminded of how bad they are or can be may be counterproductive to that goal maybe...
Also, it feels like a judgment, and a judgment from a man or men who may not be considering the entire totality of all of scripture as a whole...
Some may also think, "How can you, and how dare you try and judge me...? You don't "know me"... You don't know my "heart" or how hard I am trying to be and do good, and be better either...?"
And may say "Only God can judge me/you/them, and only God alone can know their hearts... You do not sir... And I highly doubt your own sinlessness, or you goodness, especially with or by preaching like "this"...
Strikes some as very wrong, bad, and maybe even evil...?
"Why" though, is the question...? The real why(s)...?
Some may feel that those doing preaching like this are abusing their power/authority and/or position as well...
I mean it's not exactly "Good News", not by itself, alone anyway...
If they are gonna do it all, I think they have to know how the bad news is also, or can be, good news, or a part of the good news also, and always follow up with that also...?
God Bless!