"Because the doors to the stairwells and exits were locked – a common practice at the time..."
Your quote is from a fire in 1911. This is no longer at all common practice, and would get the university in serious trouble during regular inspections.
Yes, the quotes are all from the linked articles, one of the event happened in 1911. It's not unheard of that schools also disconnect fire alarms and block fire escapes because students "abuse" those from time to time.
So yeah, maybe one of the quotes is less strong, but the sentiment still stands, that fire exists are not a replacement for main exists, as people tend to go back to where they came from, instead of seeking new exists.
2019 - a set of building exit doors with panic bars for egress gets locked closed at work presumably because those using them were letting in too much cold outside air in the depth of winter.
Reported the "locked" status to the local fire inspector, the panic bars were unlocked the next day.
So it is not just in 1911 that folks with the key to the lock get the bright idea to lock a door that is meant to serve as an emergency exit in the event of a fire or other emergency.
Your quote is from a fire in 1911. This is no longer at all common practice, and would get the university in serious trouble during regular inspections.