For arguments sake. Let’s assume the answer is, “it’s muttar”. Should you? Just because you may, doesn’t mean you must.
Why in this case not, any less than parking in any other public parking spot? An illegal driveway, by definition, is a public parking spot.
Am I greatly inconveniencing a particular person for no justifiably important reason? If yes, don’t park.
What if by ever parking in a public parking spot in front of someone’s home you greatly inconvenience him by forcing him to park in a public parking spot further from his home. Should you never park in any public spot in front of someone’s home? Why should it change if the homeowner created an illegal driveway out of the public parking spot in front of his home?