We wiped on Thok the other day after having it on farm for 5 months - it happens all the time to every guild, the random 1-2 wipes on a boss because someone fucked up or dc'ed. Early on in a tier it's pretty easy to wipe to Paragons or Siegecrafter for example - just takes 1 mistake where someone eats a bomb or messes up their Catalyst. Sometimes multiple people make those mistakes a few times in a row! It can end up eating up a substantial amount of time (1-2 hours taken from a 12 hour guild is a lot). Perfectly understandable decision to avoid that and just go for progress.