It completely is. If you're talking about one parked for dozens of minutes or hours, sure, worth getting annoyed, but if you, living in an urban environment, can't handle a few minutes of some random noise from someone just trying to get their economic sustenance while making a few of your neighbor's kids happy for a bit, you're the problem. The funny thing is how many people try to justify their specific unreasonable intolerance as something completely okay to impose on others with complaints.