I guess I'm lucky. I've never seen these people who go back and forth 4 or 5 times to back into a spot. Most people do it on the first shot, it takes about 5 seconds and they park as straight as anyone else.
Let's face it, some people are just bad drivers. They park crooked or too close to the line whether they pulled in forwards or backwards, and those trucks whose mirrors stick out 2 feet on each side are just annoying no matter which way they're parked.

But I guess I'd rather they have those large mirrors and be able to see while they're driving, than be bothered by having to dodge them while walking by.
My dd's old school had just one row of parking spots, all of them facing a brick wall. Most people backed in there, because it was obviously much safer to back in towards a wall, than to back into the lot towards the school where people are walking. It's the same in any lot, though maybe to a lesser extent. Most people seem to walk right in the center of the aisle, where the cars are driving.

(Those people are annoying, too. Do they
want to get run over?

) I've never seen anyone walking around a parking lot in the empty spaces. You're much more likely to encounter a pedestrian as you leave a spot than as you enter it, isn't that the better time to be facing forward?
Most stores, schools, etc around here have diagonal spots, so I don't back in regularly. I'm with the others on concerts, sporting events, etc, though. When I arrive, cars are trickling in, since they all have to stop and pay on the way in. They are going in different directions looking for spots in different areas. There is never anyone near enough to be bothered by the five extra seconds it takes to back into a spot.
When it's over, there are thousands of cars leaving at once, all in the same direction. If you're backed in, it's easy to inch your way forward into the long line of cars, and most other drivers will pause those couple of seconds and give you the five feet or so that you need. If you have to back out of the spot, you need a driver to stop 20 feet back or so, to give you enough room to back out into the line of traffic. Very few people are willing to do this.