worsenality

A person's increasingly unpleasant nature.
The process of becoming a grumpier old man.
A person who is becoming duller and duller.

It was obvious to many that Harvey's worsenality caused him to alienate too many people.
As with many people over 50, Joe's worsenality made him picky and judgemental.
Kim's worsenality meant less invitations to scrabble, bridge and twister. Instead he was reduced to watching re-runs of Bewitched and Green Acres