This is useful. Though I'd argue we ought to look at it a few different ways.
I'd agree, for instance, that expecting run times to fall within 20% of their ideal is, in an average party, overly demanding. But that also wouldn't account for context. Is the run taking 20 minutes because the tank is dying when the heal starts to idle? Because one or more DPS cannot, for the life of them, dodge the boss mechanics and ends up at less than half their would-be throughput? Is the run taking 25 minutes because the tank will only pull only one mob at a time? Is it taking that long because a DPS refuses to AoE? Or, is it just a minimally geared party? Given all those varying contexts possible, a fixed expectation would indeed seem arbitrary.
That said, and I apologize if I misread the trajectory of your prior posts and those to whom you were responding, my point was aimed more at quality of play itself, and the timers that convey those standards (e.g., Hard enrages in Extreme and Savage content). Similar to the dungeon clear times, if looked at as some fixed number (even if on X job at Y gear), quality of play would again seem arbitrary, but generally those numbers instead come from somewhere (e.g., some level of familiarity and effort at the minimal or likely gear levels) that connects back to making a form of player engagement pertinent and rewarding.
Citation needed.
I cannot say on principle that even unreasonable levels of exclusion (i.e., those greatly in excess, through gear or prior achievement progress, etc., of what adjusts for risk of some factor of failure, such as skill, latency, etc.) are
inherently toxic, but it will often be self-defeating. If fearmongering occludes a place for skill or merit, for instance, such as by requiring so much gear that one is carried through
relative performance that would be far below standard, it both
- forms a very different identity for the game, likely not in the direction most of the people initially attempting to improve their content enjoyment created those parameters for, and
- will likely create a trench in progression paths for which the devs will have no remedy, since it would be almost entirely a community-formed issue.
That is of course assuming, perhaps hyperbolically, that the practices spread or otherwise standardize. I'll let your own experiences judge whether that is a typical phenomenon. I can only offer that exclusive practices have seemingly tended to exponentiate slightly (or, to "trend") in each of the MMOs I've played thus far (Neverwinter, Ragnorak Online, TERA, Blade & Soul, WoW, and, ofc, XIV).
I apologize if this has seemed to give off a tone that exclusion is inherently bad. Often what we call "exclusion" is in fact just the presence of a greater number of (thereby more finely tuned/crafted) difficulty levels and differences in intended audience. Many of the things we in one breath call fundamentals of good design (such as by letting the player determine to what extent they want to engage in/with X, Y, or Z) can be turned about into derogatory meta-descriptors in the next. But, that can lead into a great many rabbit-holes (especially regarding intrinsic vs. extrinsic reward and consequent tenuous goal intersections), so let me oversimplify for now with a hackneyed, "Your actions have (subtle, longterm) consequences (that may run opposite to the principles your actions followed)."