I agree Styles was the biggest jerk, almost jerk for jerks sake. Also, Captain Keough(?) of the Odyssey in DS9, he was bad too. Jellico however, was not a jerk, he was a leader that wanted things done his way and I think he deserved respect. I've know a few 'Jellicos' in the corporate world and have a tremenous amount of respect for them, and they have always held develop their people. I found it interesting that Jellico usually referred to his subordinates by their first names and was such an authoritarian, while Picard used ranks and Mister.
I never met anyone who liked Jellicos of the coroporate world. They are usually the most hated people in the company.
PS. Nechayev looked a lot like Jeri Taylor years ago. I wonder if the writers wanted to send a message across?