I really blame the
Alrenalize album for Def Leppards status today. Sure it it sold by the truckload back then and was probably considered cutting-edge in 1992, but it didn't have any longetivity as apposed to
Hysteria. They didnt change their sound or even appearence either by 1992. (What band in their right mind would still have big hair and and tight trousers and sing "
Make Love Like A Man" the following year after the grundge movement.

)
Then by 1996 when they released
Slang, no one were in interested in, in their mind, a bunch of 80's hair band has-bins, nor did they buy into its more up-to-date experimental approach. Though fans of theirs consider it their best work since
Hysteria.
Euphoria was a decent album IMO and it was quite brave of them to release a modern-day-80's-rock album in 1999, and then
X was OK but a little to watered down for a band who created
Pyromania and
Hysteria.
I don't think Bon Jovi owe an awful lot to Def Leppard, maybe in the early days, but certainly not anymore.
Having said, IMO
Slang,
Euphoria and
X crap all over
Crush,
Bounce and
TLFR.