That's the part of the gating system -- "Raiders (having) the fear of God struck into them for wiping just once," as Lume puts it -- of which I'm not overly fond myself. A key raider lagging or disconnecting can result in a wipe on much of this content, and more particularly on the two bosses (Putricide and Lana'thel) for whom limited attempts currently exist. Both command very high DPS requirements, so even if you can easily afford the loss of a laggy DPS or two on something like Festergut (which is pretty baldly a DPS check in its own right), a single person going offline on Lana'thel-25 can wreck both the attempt and peoples' nerves. Losing 4 Blood-Queen Lana'thel attempts last week due to the bug with Kinetic Bombs aggroing her through the ceiling during the Council fight was equally frustrating.
To play devil's advocate, the gating system does have a few things going for it. As I've written previously, any honest player would admit that blowing through content isn't an ideal way to experience it. The gating mechanic also pressures people to fix their mistakes more quickly, and that's something raid leaders like a lot (let's be honest, we've all been in raids where at least 75% of the wipes were due to really dumb mistakes). And Blizzard isn't really restricting your ability to kill these bosses so much as it's punishing raids that attempt to brute-force a kill without fixing strategy flaws.
Unfortunately, this has the side effect of punishing raids for more innocent mistakes or technical problems. Ultimately, I'd guess that gated content has a different impact on each raid, and it's a bit irritating that some of this impact is out of the raid's collective control.