Warriors inferior defense to paladins was being blamed for not clearing Titan Hardmode.At the time Titan hard mode was needed to get +1 relic to access coil.A lot of time people were unwilling to try and clear Titan hm with a Warrior.This also was the situation with coil which led to the subsequent buffs Warrior got as Warrior players for a large part were being deliberatly excluded from in game content.
There were parties that proved it could be done with Warriors but they were very few.
Now judging by your join date you weren't here when it occurred and would joined after Warrior got buffed strongly as a result of what happened over Titan and coil.

As for the other examples,they are the result of a trend that was created in ARR.