With football it is easier.I don't see why people can't understand domestic games and european games, even as a casual fan. The concept is pretty simple and works fine in football. Maybe they'll have less understanding of who are the best european teams, but that's not a major drawback. The big issue you've pointed to is playing club games on international days. It robs clubs of their best players and while a good opportunity for younger players, it does take away from the spectacle. That's why a 10 team league with reduced fixtures can then maybe rest players during international breaks and with the new premiership cup, still develop younger players.
In the main
Weekends, domestic
Mid week Europe
Rugby cannot do this as all played at weekend.