Those expectations are no less worth accommodating than general expectations of etiquette. Heck, the things that allow for a run to be smoothly and enjoyably finished in the usual 15-25 minutes are all literally matters of etiquette, just ones specific to that vein of activity.
Moreover, there is no meaningful, let alone directly, relationship between the ToS and those timers, only between ToS and established community etiquette. Being expected not to AFK-leech has nothing the timer. Being expected not to sabotage the run has nothing to do with the timer. obvious sabotage is obvious sabotage no matter how long that timer is or how many minutes remain.90 minutes and ToS stipulations that everyone in the party has to be working towards the goal of meeting that 90 minutes
And when those timers were set, back in the days of pre-nerfs Amdapor Keep, people were actually hitting that maximum, not even all that infrequently. Some would disband after repeated wipes to Demon Wall, but others would end up finally getting through only to time out a few wipes into the final boss. The same occurred again in pre-nerf Pharos Sirius, for whom the first and last bosses were especially difficult at its onset. The timer's never been adjusted, but it did not begin as something tremendously lenient. The timer mattered.
But why are we affording to anything less than a legal obligation any and all leniency? We're not required to be nice to each other, only to avoid provably disparaging remarks, but being nice (or at least, not unkind, even if less than provably) should be expected, no? Why would the same not be true for our efforts in or preparedness for content, through which we not get more engaged in the game and that shared experience but also value each other's time?but I understand that's a preference and not their "responsibility" to me.