Jellico was was written to seem like a jerk so the crew would have something to react to and the fans would want Picard even more, kind of how Capt Harriman was written to look like a timorous idiot who just happens to become captain of the flagship in Generations to make Kirk look even better. It was lazy writing, imo.
I liked Jellico because he was a breath of fresh air. A little much at times, admittedly; nobody likes a new boss who just walks in the door and starts busting everyone's chops. But he had an agenda, clearly, and he wanted it carried out. The Enterprise crew are understandably taken aback by Jellico's demeanor but at times they also just act like little kids with their favorite soother taken away. Whatever, it's how the show was presented to us.
Jellico: Efficient captain, personality of a belt sander, not much for small talk and hugs.