Originally Posted by Brutone
I get your point that a starter friendly class doesn't necessarily mean than it's easy to master but in terms of DK I don't think that mastering it requires exceptional skill. Dk is just not as good as the top tier classes. It's decent but not S tier.

I think the main reason for it is that DK doesn't scale that well with high end PvE gear which gives mostly secondary stats. Warrior for expl scales insanely well with arp and crit while DK needs mostly Str and consquently doesn't benefit that much of highend PvE gear.
I think in a 264 ilvl meta DK would perform much better.
This is it. Additionally comes in the fact that bauble as a trinket, that nearly every (top rated) healer has, counters the DK's strangulate and makes alot of people survive times when they would have died for sure without bauble.