Having to explore places on foot is super cool for new players, but like most things flight paths should be unlocked automatically for alts after you've found them once. Leveling alts was *so* much more enjoyable when I could freely go to whichever zone I wanted without having to roll my eyes at the hassle of running all the way across Kalimdor to find relevant content just because I chose to do the first half of my leveling in the eastern kingdoms. It's one of the main contributors to the fact that I've just sat in capital cities queueing for dungeons on my last few characters.