These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Idiot Plot: The only way half of the situations in this movie are able to happen is because people behave like brain-dead morons who don't know what the word "fire" means. Of course, this is how many people behave in disaster situations in real life, so it is arguably justified.
Nightmare Fuel: The movie is full of it once the fire starts in earnest.
The ghastly results of a bunch of people from the party panicking and trying to take the main elevator down past the fire floors. It doesn't end well.
This actually gets even more horrible. A few moments later in the movie, an elevator opens to the party room and a burning man staggers out, who dies after seconds. Look carefully and you notice that it is the same elevator (you saw the doors closing again in the inferno). Considering what we see inside the elevator cab, it got turned into a freaking massive cremation pile consisting of a mass of burning human bodies.
Bigelow running straight into the blazing inferno with nothing more then a coat for protection. It doesn't end well for him, either.
His secretary's death is even worse. She's blown out of the apartment by a backdraft, falling to her death. While on fire.
At one point, while the fire chief is attempting to escape a broken elevator, a burning body falls past him and his crew — another firefighter. One of his companions almost BSODs on the spot. Perhaps even worse is when the chief comes upon another severely burned firefighter casualty.
"The ceiling fell in on him and by the time I got to him, he was covered in hot stuff..."
The triage ward toward the end — a seemingly endless stream of broken and dead firefighters. Still Harsher in Hindsight (as with much of the rest of the movie) after 9/11.
Seinfeld Is Unfunny: Considering how this was made in the 1970s, one can probably see it now and wonder why the hell modern conveniences we have today aren't being used. The elevator scene and several action stunts probably look incredibly corny. Heck, even the concept seems pretty stupid today.
Though, there were a few comparisons made between this movie and real-life events when 9/11 occurred.
Tear Jerker: Lisolette's rather thankless death even bothered test audiences, though it sets up a very bleak Downer Ending for another character.
The firefighters taking heavy casualties and fatalities, and yet they can't fight the fire effectively.