This release (and many before it) demonstrates a lack of a clear vision of where ArenaNet wants to head with PVE content. The game was billed as epic battles and no trinity, casual friendly, etc, etc, etc. As new content has arrived you have consistently wavered from this with things like FoTM, Teq and the latest boss fights and the more aggressive usage of time gating.
I know coordination can defeat these events but the overflow system (Lornar is capped before you can even have a full 25×5 zerg for the Marionette fight…) , massive lag due to new content, and most of your player base being more in the casual category puts everyone in a bad situation. The coordinated guilds now are sitting in maps for 1-2 hours to wait for content (how you did not see this coming and why you think it is OK is beyond me when Teq is basically still affected by this syndrome) so they have a chance to not have randoms interrupt them. All these things add up to being the exact opposite behaviors the overall game design promotes and why so many casuals are so confused about the endgame.
Suggestion: Make the hard events easier for the general anonymous Zerg to clear but greater rewards for faster clears or doing bonus events. A proper tiered reward system (not the current bronze, silver, gold mechanism which is effectively useless in the game) would solve your problems. This would still allow the best PVE guilds to strive for bragging rights and do things like posting videos of how they now kill Lupi in 20 secs that 99% of your player base does not care about. It would actually reward them for improving and getting better but not punish the general game system you have setup that is tailored to the casual population. This would even allow you to take other existing “normal” fights and add extra events or speed clear timers to them to make them harder for the coordinated groups. Some bonuses could even encourage build diversity. IE: No players downed during the entire fight or a fight that can only be done via condition damage.
For example: What if when doing the Shatterer, a second group of players could break off to a side event that required coordination. Lets say they have to defend a big cannon in a area that capped at ~20-25 players from waves of champions that have different fight mechanics (now you can go crazy with the stuff the general population does not want to deal with). If this team succeeds for X minutes, the cannon would kill the shatter and the whole event would finish early and everyone gets a greater reward. If they fail, the Shatterer still dies to the main zerg outside (probably slower since 20-25 people are now doing the other event and adding a slightly higher risk of not completing at all). This would create better end game progression by equating difficulty and progression with coordination & skill (and if done right, build/gear diversity as well, which is better for the economy too) rather than artificially with something like AR.