Going to the match is all about routine.
You leave at the same time, normally with the same people, take the same route, same pre match rituals whether that be programme, food, drink.
When you get out of that routine, it is hard to get back into it. I fell out of that routine four seasons ago, still got my season ticket but i now find it a chore to go to the match.
Many reasons happen for getting out of the routine, family, work commitments, finances. For me it is simply the pain and the stress of actually getting to the ground. Long traffic ques, park miles away with a 20 min walk, then a 20 min wait to get in sometimes with awful security measures (i sit in SS3), shit pre-match shenanigans, shit half time shenanigans and the the tiresome journey home in traffic. The only thing about the so called "Matchday experience' that is great is the game itself, which i can see on TV anyway, in the comfort of my home without all the stresses noted above.
For me, too many city fans have lost that routine. It starts by knocking off league cup games (which i did), then FA cup (which i did) and now Champions League (which i have). The point where it was all lost for me was the Liverpool second leg last year where i decided to watch on TV instead of paying £40+ to see it live. I can never say i will never go to another Champions League game again but the chances aren't very likely as i will always favour the stress free option which i now actually prefer.
This may not be the same for most city fans but it is something that i have noticed with those i know or close to me.
Every City fan should be applauded for going tonight but for all the right we have done both on and off the pitch the last 10 years, unfortunately IMO it has been at the expense of what really matters and that is the match going fans and it will only deteriorate in the coming years as the club continue to ruin it and the sport itself becomes more and more saturated on TV.
For something so simple to get right, the club and the sport have overkilled it all and you get the product that is served up now.