Anyone can have a bad day and I have driven both. Its not just parking, its the tailgating, the cutting off a driver after passing, speeding, speeding up when getting passed, not using the right lane when going slow up hills, two slow trucks running slow next to eachother, it goes on and on. We see this all day long every day. A few drivers seem to know what they are doing but most dont. The real bad thing is the bad drivers think they are good and think everyone should get out of their way.
The thing about parking is there are no excuses be a pro, if you dont have the skills go get them, if you are to tired to park you should have stopped long before you got so tired.