The Celine cover was indeed a travesty, but I've listened to the Home Sweet Home video twice now and didn't think Miss Underwood did a bad job singing it. Are you talking about the rockin' body movements? If so, I agree it's cheesy, but live music is all about putting on a show. 99% of the people in that audience thought she rocked that song and had a good time doing it.
Have you ever gone to see a band that was killer musically but just stood there and did nothing? They hit every note exactly right and never made a single mistake, but didn't do anything exciting at all. Did they have a good crowd? Did you go back to see them again?
When I've got a killer rhythm section that I know is going to nail every downbeat at the exact right moment, just standing there with my eyes closed and playing in sync with them is a borderline religious experience. However, if I just stand there in the shadows with my eyes closed the whole night the people in the crowd will either think I'm bored or mad or not having any fun. The general population doesn't know what we musicians know and they don't care how we feel. They paid the cover change to get in and damn it, the demand to be entertained! I used to get all sorts of feedback from my friends about how I didn't look like I was having fun. Now I jump around on stage, poke fun at the bandleader behind his back and say risque things into the microphone in between songs. It's all for show and doesn't represent who I am or how I feel in the slightest, but it's what people remember and it makes them come out to see you again.
And just to be clear, I do NOT like Carrie Underwood's music.