Very recognizable,
IMHO your coworker received job satisfaction from maintaining a broken system and dealing with the issues: in other words: treating symptoms.
Then you came and wanted to fix the system: in other words: cure the disease.

This is  cultural issue and can not be solved easily. Your coworker needs to change his attitude from treating towards curing.

This is hard, and hopefully they can be encouraged on this track. Their passive-agressive and immature reaction does not bode well though.

Best of luck with this one!!