Now this is where the lines get blurred with with how the club see the fans, what they want for the future and what being a football fan used to be about. If they see football as an entertainment where you're charged a premium price for the privilege, then why wouldn't they leave? If you paid £100 for a concert ticket,but the group who are usually great are absolutely crap and getting worse as the night progresses, do you wait to the end to give them a standing ovation or do you think, fuck this let's get off back to the hotel bar?
Of course most of us who've been a fan for years know you support a club because they're in your blood. You hope you'll be entertained and successful in the process but you also know and accept that isn't guaranteed. You'll usually stick around to the end out of loyalty and love for the club. I feel that's being watered down now so the same feeling isn't there. If the team are putting on a shit show on the pitch, suddenly the early bus,train, drink in the nearest bar or hotel looks more appealing than standing there freezing for fifteen minutes of a game that's already lost.
I'm just putting some reasons out there why people would leave early. Actually the thought that you'd spent a fortune travelling all the way to Portugal to witness a horror show might make people think they are more entitled to fuck off early. They've done their bit, hanging around for the final fifteen minutes at 4-1 down won't change anything. The players would probably think thank fuck everyone's gone we can get out of here sharpish instead of going through the motions of applauding fans applauding us for getting hammered.
Just a few thought. Again each to their own. Everybody has paid their money, they make their choices as is their right to do so.