There are plenty of times when being late isn't a big deal. When others have to wait for you however, you are signalling that you don't value their time. It is perceived as selfish. I'm not saying that you are selfish, it is just that it can be perceived that way.
If you're lucky, people will start telling you that the meeting is at 8:45 just to get you there on time. Some places lock the door when the meeting starts. I had a friend who would always be late to our lunch appointments. When we instituted "late guy pays", things improved. ;-)
You can try to find a job where your problem doesn't effect others but you would be better served if you just learned how to be on time - at least until "habitually late" becomes a protected class. ;-)