One of the actual technical reasons why dubbing can look so off, is because most commercials are still shot on film, then they go through the Telecine process to change them to video for television, changing the speed from 24pfs, to 25fps or 30fps. This obviously changes the pitch, but when you also have multiple different versions, for different markets and not a huge unlimited budget, you are going to get dubbing that is off. It's hardly the end of the world though.