Considering they let the air out of the tires and left a polite finger-wagging note, I don't think they skipped the gentle reminder phase.
Daily reminder that property damage is not violence, but random acts of property damage isn't the same thing as genuine activism. We must be mindful of the purpose of a political act, and whether the act actually accomplishes that purpose. What is the purpose of inconveniencing random SUV owners? Will this affect any change, or will it merely entrench people's existing attitudes?
Imo if you're gonna slash tires, do it to the politicians. More news coverage, clearer message, and you don't come off as petty against people for having the "wrong" kind of social performance (eg driving an SUV instead of an electric) and trivialize the issue.