I would actually love to level up a damage dealer. In the past few years I leveled up three tanks and one healer. But only in Original WoW did I ever manage to level up a DD. Why? Because DDs can't level by doing LFDs. The waiting times for DDs are anything between 15 minutes to 60 minutes during leveling. That's too much. It would mean that I had to play the leveling game; which I tried. But I can't. While the story lines are sometimes mediocre and sometimes good, the meat of the leveling game is too trivial and too monotonous to be bearable for more than an hour.
I considered playing a DD up by battlegrounds, but for that to be any fun I needed heirlooms. And I won't grind heroics for a few days with my priest just so that I can buy heirlooms. Forget low level PvP without heirlooms. No matter what you think about it: the balance is even worse.
The remaining alternative would be questing with a DD in grey items. And no, thank you.
Blizzard are you reading this? The endgame has always been a problem for any MMO. But the leveling game, especially the leveling game in WoW with its many different starting locations and different classes / speccs was always a success. It isn't anymore. And since raiding-to-gain-items-to-raid stopped being fun late in TBC, I'm stuck. I just can't figure out how to continue playing WoW at this point.
Different topic. I put some youtube videos online to prove that WoW actually does try to teach the new players raid mechanics. You can see for yourself why this fails. And even if it succeeded .. I'm not so sure I even want Simon Says while leveling, too.
Oh, and if it weren't phasing it were a bug, I guess.