Retraining/reteaching/explaining DKP yet again for the 4th week in a row because DPS is a revolving door of mediocrity sucked.
Way more than hunt for a tank and healer, who generally knew what they were supposed to do.
I think it depends on the size of your guild. My best WoW experiences were in a 10 man raiding guild with two core raid groups and an open raid night. Tuesdays and Thursday were raid nights, and we'd run two teams simultaneously. The A team, which was invite only, and the B team, which was typically 5-7 regulars with the remaining spots filled via guildchat. In A-team we all knew each other, we knew we'd be raiding again together next week, and there was never any loot drama. If two people wanted the same drop, they'd link what they were upgrading from and most of the time somebody would say "you need it more than I do, go ahead." If not, they'd both /roll for it. Teaching boss fights was rarely an issue. It was a progression guild. During the learning phase of a new raid, we'd read the fight strategies and watch the videos. People generally showed up knowing what they needed to do, or at least being familiar with it enough that somebody could explain it easily. And once a raid was on farm, everybody knew what to do. If you didn't, you generally didn't get invited.
B team was mostly a core group of good players in the guild, led by an officer from A team who missed raid night, or one of their alts. When there weren't enough people, it went out to guild chat: "need 1 heals and 2 dps for X, leaving in 10 minutes, msg me if you want in." That group tended to need more explaining, but it was usually at least half experienced players, so there were as many people able to explain as needing explaining. And since we had the B team, anytime somebody from A team couldn't make it, we'd bump somebody from B to A, then fill the empty B slot from guild chat. And since it was pretty common that we'd have unfinished raids, often an officer would open them up later in the week let people see and get trained on late game content. "Hey, we never finished Ulduar. Who wants to try Kologarn? Never been to Ulduar? No problem. Raid resets in a few days anyway. Give it a try." So even if somebody wasn't good enough or geared enough to be in the core raid groups, they'd still get to see content.
Then we did 25 mans on weekends, open to the whole guild on a first-come-first serve. Empty spots went to pugs. Those nights generally involved a lot of explaining. But we handled it with open rolls. Everybody was allotted two two pieces of gear per night, a "main" and "offspec" piece. Raid lead would link a drop, then call out main rolls. Anyone who wanted to spend their main roll would roll. Whoever won the roll got the drop and lost their roll for the night. If nobody rolled for main, he's call for offspec rolls, same deal. And if nobody rolled on a drop, disenchanted and into the guild bank. Fast, simple, not a lot of extra accounting, and no needing to convince pugs who might never show up again that they needed to accumulate DKP that they might never get to spend. Mounts and things were open rolls to anybody who didn't have them. Teaching fights took a lot more time on open raid night, but since half the time they had pugs, that was just something we accepted. If you led the raid on the weekend, you knew you'd be doing a lot of teaching. Typically five minutes for every boss, and on some especially complicated fights, sometimes more.
In guilds where every raid is a 25 man, it's more difficult to have that kind of arrangement. Things are more complicated. There's more drama. It's a lot harder to get a core group of 25 people who will be there every night and will take the time to watch 20 minutes worth of fight videos if they don't know the fights. And it's harder to bring yourself to teach fight mechanics to your couple newbies, every single boss, every single time, all while the 15 people who know what they're doing stand around waiting for ten minutes. Or to be the guy standing around for every single boss fight, every time, when you and half the rest of the raid know what to do.
The worst, though, is the small guilds trying to be raiding guilds but that just aren't big enough to do it.
Every raid it's a struggle to find people, teach people, fill roles...I generally didn't stick around for guilds like that. Too much misery and drama.