I will not assert that punctuality is not a choice; however, I do think it can be unfair to necessarily think it is a lack of respect. I am often late to work, class, seeing the gf, etc. but my choice is not an active choice that I don’t care if I’m on time but a passive one because of my lack of awareness.
Here’s a common example, its 6:00, I just got home from work, I call the gf and tell her I gotta work out, and I’ll be there by 9:00; 2 1/2 hours to work out (yes, I’m a gym rat), 30 minutes to get there… perfect, right? WRONG! Both of those times are correct, but I forgot to account for the drive to the gym, the drive back, taking a shower, etc. Next thing I know I’m 30 minutes late, and its for no good reason than because I didn’t account for other things I have to do.
A similar example, I have routine appointments with my Chiropractor and I usually see him on my day off during the day, so there’s no traffic, and it takes about 20 minutes. Sometimes I make an appointment on a work day, and I’m ALWAYS late when I do that, because I fail to account for the increased traffic, which turns a 20 minute drive into a 60+ minute drive.
Obviously, the choice is to try to take into account that I won’t take everything into account, and when I do, and the things that slipped my mind come into play, I’m on time, but it’s not a simple task.
On the other hand, I used to have a friend that was habitually hours late. I remember one time specifically where we had to leave my house by 6:00 to get to a concert on time, so I told him be at my house by 2:00 (attempting to account for his habitual tardiness). I remember calling him at 1:00, his mom said “He just woke up, he said he’ll hop in the shower and be there in an hour.” I called an hour later and got the exact same message, repeat several more times, until I call at 5:00 to find out he had left “five minutes ago”, and he doesn’t arrive at my house until about 6:30 (even though it took about 25 minutes to drive, I still can’t figure out how it took him 90 minutes). In my opinion, THAT was a conscious lack of respect, because it wasn’t that he failed to account for things, but rather, knew how long it would all take and, instead, chose to go back to sleep.
Now, I’m unsure where exactly in that continuum your friends exist. If you feel it’s more toward simple absent-mindedness, you can decide whether you can live with that or not. If you feel it’s more toward disrespect, you can decide whether or not you still want that friendship.