It goes well beyound one match, Rangers and Celtic will play each other 7 times this season, it really is a joke, there's no time for anyone to calm down, before they are playing each other again. There is no doubt that their rivalry is deep and hostile fully based on religous bigotry. Celtic beat Rangers 3 nil a couple of weeks ago in a league game, that will still rankle with the Rangers players, managers and supporters.
The SFA are again talking about changing the league structure, but the 'Old Firm' have so much clout, the league will not change if there is any chance that the big two may have to share a proportion of the revenues that are generated by the Scottish Football League. The sooner they get back to teams playing each other home and away, plus cup matches, the better. If that means the big two playing at some smaller grounds so be it, it would be good for Scottish Football, and allow smaller clubs to develop and keep good players. But no doubt such sentiments are 'pie in the sky' and Scottish football will carry on being dominated by these two clubs who don't give a monkey's about the bigger picture.
I don't know what has happened to Neil Lennon, but his character seems to have changed since he became the Celtic Manager , he is really aggressive and not just at old firm games. Celtic are currently appealing a 6 game touchline ban because of inappropriate response to the match officials. He seems to struggle with the 'politics' of the managerial role, throw in the 'old firm' rivalry and it is not a good mix. He is certainly not a good role model for any football supporter irrespective of their age.
He certainly is disliked presumambly by non Celtic fans, he's been subject to a personal attack on the Great Western Road in Glasgow, and has received death threats, I don't ever remember any other Manager of Celtic or Rangers being subject to this kind of abuse. I am not saying that such behavoiur is acceptable, far from it, but it does highlight the strong feeling he can generate amongst certain people and that spills over into the general supporters and how they respond to each other.