Can't say I'm surprised - they've been living on about 18-20 players all year, and one social event involving half a dozen blokes could take them out for a weekend. They got pretty badly smashed against Savers, so might also have some injuries.
And, to be honest, there's not a lot of joy travelling to Holroyd to get the shit belted out of you. Its not anybody's fault that stronger clubs exist, but the physical and psychological punishment of getting stomped will take it out of a club EDIT: particularly if there isn't a finals spot on the line.
Subbies need to do something to have graded comps in the lower divisions, or clubs are just going to shrug and walk away.