Some people (probably a minority) prefer midweek games if they work weekends and vice versa, so European games may suit them better. So cross competition loyalty doesn't suit them. They should imo be entitled to a european cup final ticket if they attended every European game for example and no home league games than the person who attended all home league games and no european games.
Personally prefer the way it is currently.
Surely the people who watch Liverpool the most deserve to go? As an example, my Dad is 16000 on the waiting list and as far as the club are concerned he's been to every game bar Euro aways since 2011. Now, he wasn't going to Kyiv, and the credits for the aways aren't used by him, but they don't know that. Should that level of support be treated the same as someone who's done, in theory 6 home games in Europe this season?
Ultimately there's no way that leaves everyone happy.