No one said that they were not needed. :R
The majority of them, not all, have unsafe driving habits.
Just look at the pictures of the big pile ups during weather events. Almost all of them are caused by semi's driving faster than conditions.
Can't tell me none of you have been driving in a dangerous snowstorm or rainstorm and the semi's are just flying past you never slowing down.
You and I do that and you'd be pulled over but the cops seem to allow them to do so which ends in fatalities of people in cars. Just saying see it all the time. :(