People expect you to know what’s going on in this game because it’s been out for almost 20 years. Not saying that’s an acceptable mentality, but it’s the truth.
Also, everything in end game instanced content is essentially competitive. Go faster, go harder or don’t waste my time is the general approach for a lot of players.
That mentality even found its way into classic wow where people wanted an optimal raid group to clear Moten core in record speed even though people were 2 manning Onyxia.
Until Blizzard fundamentally changes how end game systems work, the pug life will always be this way. The only solution is to find a guild who doesn’t rush.