There's any number of reasons why the attitude expressed by the OP is completely wrong in the context of what we're trying to achieve over the next few seasons. Saying sack the EL off in favour of the PL misses the key point.
1) While I'd love it if we won the PL, apart from the fact we've won it there's actually no great monetary or other value between winning it and coming second.
2) Barring a complete disaster, we'll be in the CL group stages again next season which is where the big money is. At this stage it's more important to secure that qualification and revenue stream.
3) There is no guarantee that going out of the EL would help us win the PL. After tomorrow there's only a maximum of 5 more EL games to play. We could be in the FA Cup and still end up playing 5 games.
4) We've won just one trophy in the last and it's been 42 years since we won our sole European trophy. I'd like more trophies & I'm amazed Blues can be so sniffy about what is still a major European trophy.
5) We get UEFA co-efficient points for the EL, in the same way as we'd get them for the CL. Getting to the final may get us into Pot 2 of next season's CL draw, which could be the difference between getting to the knock-out stages and dropping into the EL as we did this season.
6) I'd expect us, from next season, to be regularly challenging for the PL, the CL and the FA Cup so the EL this season is good practice for that.
7) We keep saying the rags are weaker than they've been but they're currently a point ahead of us in the league. They're in that position because they play every game in every competition to win. There's no way Baconface will be sending them out tomorrow with an attitude of "Fuck this lads, just take it easy so we can go out and concentrate on the league". Winning is winning and breeds a mentality of playing through the tiredness, pain & other difficulties because a win now is more important than being tired tomorrow.
Once you start thinking that this game or that competition is unimportant then you start to lose that. I've not seen that winning mentality in the City team yet and the EL will be a test of whether it's there or not.