Something similar happened during my very first WoD run this weekend. In the alliance I was assigned almost half of the party were people who were running for the first time (including myself). And it was made apparent very quickly because usually our alliance was the poorest performing out of the three because we just didn't know how to do things. (And yes, I watched a video. Explain that in a sec). Don't know how the other two alliances were made up. We did fine for the most part until we fought Cloud of Darkness herself.

We wiped twice, both times we actually got the boss to its last third of health. Twice someone initiated vote abandon which was refused, so the people left. Someone from the other alliances asked if there was stuff we didn't understand, so I and a few others finally explained why our alliance was lagging behind (now that we're standing still long enough to actually be able to type/talk). They explained things guide videos did not, we got our replacements, cleared the raid on that final third try with a drastic decrease in player deaths (mechanics handled perfectly I add. She didn't get any clouds swallowed or anything like that).

It really does amaze me how quick players are to flat out give up rather than take a second to see if the group needs to adjust.