well, promotion also has fringe benefits. you get a promotion bonus, and the weekly income from both ticket sales and tv contract are significantly increased. so while you may demote your first go-around at d2, it's not a lost season. promoting still serves you extremely well, even if you get worked in your new league and demote right away. you can amass capital, allowing you to do all sorts of things. you could spend the season restructuring your team, making massive arena expansions, simply amassing money for future buying power, 100% focus training (perhaps training way way out of position), spend a shitload in scouting knowing you'll be getting a/the top pick... maybe all of these things all at once.
i for sure know that, if/when i do promote, i'll be demoting immediately. i need a bigger arena and a couple new trainees, and need to restructure my team. i can just use the league minimum salary and spend the season doing things that improve my franchise value, so that next time i promote to d2, i'll be ready to stay for good. i'm all for the idea. it keeps leagues fresh and presents new challenges every single season.