I can only see this as that these clubs see this European Stupid League as instead of PL, Serie A etc.
They say that their players shall play less games, but that would not be possible in the 20 team ESL that they are suggesting. Even if they do not play in the CL and domestic cups they would still be playing about the same amount of games. More if they were not in the CL or get knocked out early in any of the three..
I think they want to break away. Imagine, in their greed infected minds, how they could then fill up the free time with games against top teams in South America, Asia and even the USA? Money, money, money ...