I have almost never given 1-star reviews, and the past time was two years ago. This is to emphasize that Asiana has really earned this low ranking. We flew ICN-JFK.
Asiana was by far the worst of the 8 international first class services we've used. As a quick overview the food was bad, the catering terrible, and the service unbelievably awful, resulting in a long and unpleasant flight which should have been enjoyable.
The first class lounge before the flight was like a low-end business one with mediocre and minimal food, and a loud waiting area above and open to the busy terminal. A bad lounge compared to others, but we were saving our focus for the flight itself so weren't concerned. In retrospect this was the best food of the experience.
Dinner service is when things starting going downhill quickly. We had preordered meals, which were not at all as described. They were bland and left largely untouched by us but for a cursory taste of each item. This should have been no problem as normally 1st stocks lots of options, but it was not the case here. It seemed like they didn't have any other choices, all the other meals were either 'already ordered' or not on the plane. This is in a small cabin that wasn't even full! It could only have been a case they didn't get the food loaded properly on the plane. They didn't even have cheese...
Six hours before landing (4:30am) when all passengers were sleeping, two of the night staff, eventually joined by a third, made themselves cozy in the empty first class suite immediately in front of us in row 1. For more than an hour they had a loud conversation that included laughing and woke everyone up.
With everyone awake, we started ordering breakfast, which were denied as "they weren't ready yet" (first class is supposed to be dine on demand), and asked to wait an hour, which ended up being more than 2. They offered to prepare the 'anytime' items, which for this flight were just Korean soup and ham sandwiches, which we declined. When breakfast eventually came it was better than dinner, but still only a business class level at best.
This is very much a 'first world problem' scenario, but these flights cost over 10k. Most business class experiences are better, and I have even had better food, wine and service on one Air France economy flight. The only way this was first class was the seat with a door, and champagne (but Rothchild, not Dom or Krug). When service was not ignoring the passengers (water was never refilled even once unasked in a 15 hour flight), it was telling us didn't have what was on the menu or preventing us from sleeping.