Shadowmeld is hella broken...
I am a night elf because Akraen was a druid for thousands of years under the tutelage of Staghelm. The Cataclysm awoke within Akraen the desire to pursue his affinity for the advance of arcane magic and after his counsel with Mathengryl he decided the best thing was to leave the Cenarion Circle and practice the arts of the mage. Elune frowns upon the use of fire magic so he is mastering frost and arcane.
But really if I cannot out play the racial then I do not deserve to be a raider. I beat every other mage of every ideal race that I can find.
If you are someone who thinks changing your race will fix you then you are a retard. Stop looking for easy fixes and start looking introspectively.
Personal preference on cast animation for me. Out of all the alliance races I prefer the Female Draenei cast animation (for caster dps) and then my shaman is male for their attack animations also because I am not a huge fan of what most gear looks like on Dwarf and Pandaren. If it wasn't for me playing Alliance, I would never stop playing an Undead Female Mage simply because I love their cast animation. I personally think it is the best hands down.
I don't think anyone was offended, well Akraen might have been :P. Just some people like a particular race and take advantage of the new classes they can be, some just love the way the gear looks on them, and many other reasons come to mind. Just about everyone has their own likes and dislikes is all it comes down to.
Mind you, that mage did become an Undead because that guild closed shop faster than 4.3 became unwelcomed after being released so maybe it's not the best example.