I really don't think the lore is as bad as people make it out to be. It's a game, so the lore will obviously be driven by the game mechanics and the needs of the game, but I think they often do a good job with what they have. I never had a problem with Blood Knights, since I always assumed the high elves would have a variation of the paladin. I actually thought the story of the Naaru was what made it frivolous, not so much the class. I think that is why Blizzard decided to make them more "classic" Paladins following TBC.
The draenei as Shaman I thought was a bit odd (the draenei in general were really odd), but they did a good job showing how shamanic the Broken were, which helped cement them for me. Dare I say the "orc homeworld" involved more draenei and blood elves then it did orcs, which I thought was a mistake. Though blood elves are now barely represented compared to orcs, so it evens out I guess.
Maybe I am just overly accepting, but I have known for a long time that Chris Metzen is a proponent of the "Rule of Cool". He will change a section of lore if he finds it would be "cooler" to do it. Draenei were actually a cause by this, one he apologized for, but ultimately I think he made the right choice. Draenei are probably one of the more popular races I see on Alliance, and have a pretty large following in many communities. Remember when the orcs were a bloodthirsty army of evil that burned cities to the ground? To most WC3 players, the sudden honorable Horde lead by Thrall came out of nowhere, yet we all accept it now as just a part of the race and the history. In a few years most of us will not care about Tauren Paladins or Night Elf Mages, they will simply be another step in the history of those races.
I am not going to attempt to convince people to like the lore as it is, that would be a foolish gesture, but I do wish to explain my case in any event.