Before we traipse merrily down this yellow brick road, given the reputation I've quickly earned as a rabble-rouser, let me say I'm playing this one perfectly straight -- I have an honest desire to learn why some people treat levels 1-70 as a pre-season of sorts.
I'm pondering undertaking a fast leveling of my own. I've hit a not-to-uncommon issue: I met a group of people in real-life who not only play on a different server, they had the unforgivable gall to play a different side -- I'm Alliance; they're Horde. I'm very much a "the journey is a destination unto itself" kinda guy. Hitting max level for me is somewhat of a let down. I enjoy dinging, getting new abilities, etc. That side of me is combating with the desire to quickly get to max level so I can play the game with them. I definitely feel playing the game with real-life friends is the way to go. This is one of the reasons I'm looking forward to Patch 2.3. I can get my lowbie to 20 before the patch hits and then enjoy the Horde content and level quickly as well.
So, to you those who can't get to level 70 fast enough, why? And does the potential to miss out on some lower-level content as you blast past it bother you?