Exactly. It's ridiculous that we chastise people who only go occasionally - there could be dozens of reasons why and football doesn't have to be all or nothing like it is for many of us.
The idea of a 'hardcore' is also slightly ridiculous to me too - people drift in and out of support for family reasons, financial reasons, get too old, leave the region, come back etc etc. They can still be proper supporters just because personal circumstances mean they can't or don't go to every game, or have to pick and choose. And when we have low crowds, the assumption that those present are the 'hardcore' is silly too - some of them may be obsessives who never miss a game, but others will be occasional fans who just happen to be around that day/have some money/fancy taking in a game/tourists/whatever. I was in plenty of c15K crowds at Roker when I was just an occasional attendee as a kid...but wouldn't have considered myself 'hardcore' at the time (I was obsessed, but didn't go regularly because nobody would take me or I didn't have the money to go). I'm now probably what some would consider hardcore (at least in terms of a home fan, ST for decades, though only an occasional away game these days).
Also, like with anything, those that only go occasionally sometimes then become those who go always, simply because they get the bug for it. Welcome them into the fold, don't exclude, appreciate the fact they are there FFS. We all have to start somewhere.