Anyone who wonders why some might follow a king who is headstrong and thousands of years younger is obviously neither Japanese nor British nor Swedish nor etc...
Ask a Brit why they haven't put the royal's heads on pikes over London bridge yet? Or at least... served them with an eviction notice and maid service bill.
The concept of royalty as something important rather than to be ridiculed is deeply ingrained in some cultures. And it won't matter how bad your royals are - they are -YOUR- royals. We Americans wrap ourselves in our flag, the Brits wrap themselves up in the royals. The greatest fear the Japanese had during WWII, was not getting wiped out to the last man woman and child - but that they would lose their royal family. And despite both of these nations now having royals that just show up at parades and give a royal-wave to the crowds - they are still in place and still a very core part of their self-identity.
Now I'm just guessing the comment was about elves - but it fits for any immortal race too.
If you think of elves as beings that live for eons - they're probably pretty thick in the head and stuck in their ways. The average elf would make your great-granny seem like a raving techie-liberal-lunatic. These people probably don't do well with change. So if somebody comes along and is a complete dolt, but has the right bloodline - that's the king. And they won't have no ifs ands or buts about it.
It'd be a lot like when US forces showed up on the great plains, went to the tribes and said 'take us to your leader', and mah boyz took em to a pack of old grandma's. The Americans came back with 'no, your leaders, not a pack of useless old women. Bring us your leaders,' so we looked around and noticed their guns and thought... oh, they mean our war conucil... yeah, where's gramps at?
The elves are likely to show up anywhere and be completely blind to the ability to see leaders that are not royals of the 'ancient bloodline' - no matter who you put in front of them, they'll just look back at you with 'ok stupid, we said leader' until you show up with a guy who's got a crown and a pedigree.
Again, you could make the same or similar comment about most of the immortal races. And for any culture stuck in its own ways - its going to presume others act the same. Stormwind's king may be there in large part because elves and dwarves have no idea how to speak to a leader who is not a king. The draenei probably look at anybody missing tentacles and think 'freak', then proceed to lord over them with 'priestly advice from the prophet' while claiming to follow. And the humans of the various nations all look for monarchs in their cultures. The gnomes... here I realize I don't even know enough about them to say anything...
WHOA Rational thought in a Blizzard Hate thread..... say it aint so