Not being promoted also has it's perks too — your players have a star added. Some managers do it intentionally, it's called "tanking". It's done to improve players quality, since on an average a young player can gain a star each season. So at the beginning he was 5*, by the end he became 6*, and when the team promoted, he became 5* again. But when tanking, he'll become 7* star in 2 season, thus becoming 6* the season you promoted.
I'd personally be happier finishing 8th-14th than 5th-7th, but this mentality of mine might change if I were Level 30+.
Yup! Thats one of the perk.
But major thing is that you become fearless.