How can I prevent my machine from automatically downloading deleted system files?
I stumbled across this yesterday while performing maintenance on my server unit. Give it a shot and let me know the outcome (AFAIK this is only viable on Yosemite).


Open 'System Preferences'
Select the 'App Store' pane
Deselect the checkbox marked 'Install system data files and security updates'


Hopefully, OS X should stop repairing your Extensions folder each time you connect to the internet.

Failing that, perhaps changing permissions for the kext (rather than outright deleting it) will just cause it to fail to load but still be present and therefore not re downloaded.