Here is my position and I will leave it at that so I don’t attract the wrath of my old colleagues:
If someone decides to take a certain action, knowing the consequences potentially attached to that action, it does not matter if they took that action in a moment of “passion” or in a premeditated, planned manner: they should face the consequences of their action.
And rules/laws against pitch invasion are incredibly important to maintaining order at football (and similar rules/laws for other large scale events), as is enforcement of those rules/laws as deterrence against violations of those rules/laws.
Almost no event—football match, concert, festival, etc.—has sufficient crowd control to stop more than a few people from entering the pitch/stage/restricted area, so strong deterrence is really the only thing maintaining order. It is a social restraint mostly based on collective agreement on appropriate behaviour and fear of consequences of acting outside of that appropriate behaviour.
And all of that applies equally to fellow blues as it does to fans of other clubs. It has to, otherwise we are exactly the sort of people we regular decry and ridicule: those that believe they should be able to do whatever they want without consequence.