Palace made it to to a Cup Final a couple of seasons back, Southampton made it to the League Cup final last season. The glory is still there in football for those outside the top 6.
I'd argue that it means even more now because of the struggles with the end of the Goldstone, Gillingham and...
I understand your overall point here, however there's no cast-iron guarantee that relegated teams are going to perform better in a lower division.
The better players leave whilst the lesser players stay on significantly higher wages than in that division.
Lower crowds, massively less TV money...
If it doesn't matter what league you're in, it's worth staying in the Premier League for the money alone.
And if Sunderland and Wigan had stayed up, their supporters wouldn't be experiencing the pain that they are now.
As for the "looking forward to relegation" comment, it's probably not worth...