Yeah.
Another big reason people want him gone is because they view Kidd as basically representing cronyism; he's good friends with one of the owners (I believe he was in the owner's wedding or vice versa) and fans want a more traditional chain of command. They think (and it's possible that it's true) that Kidd's opinion takes precedence over the GM when it comes to personnel moves.
I think it's possible that Kidd is our Scott Brooks/Mark Jackson: the right guy to develop the team but not the right guy to take them over the top. Milwaukee also has a ton of Greek/Australian fans, and due to them following European ball more than the average fan, a lot of them want to hire that Messina guy that I believe is an assistant for the Spurs and was a legendary coach in Europe.
Edit: And consider this regarding Kidd's defensive scheme:
Bucks starters:
Malcolm Brogdon - good defender
Tony Snell - good defender
Khris Middleton - good defender
Giannis Antetokoumpo - good defender
John Henson - good defender
The Bucks are the 2nd worst defensive team in the NBA, only behind the Cavs.