Definately not alone

I really dislike PvP and rather focus my time on raiding or instances (I like getting new shiny things all the time ) so when I decided to multibox I looked at what classes I had on my account already, worked out what I'd want for a good instance group (needed tank, heals, cc, dps...this was before I watched the videos of pure shaman pewpew) and then narrowed my choices down. Since I already had a holy paladin, warlock and rogue on one account I decided to build a group that could fit them in in the future if I wanted to so that led to my choice of prot pal, holy priest, 2 mages, shaman. I put one of the mages on my main account, so now if I want to I can swap out the mage for a t4 holy paladin (and respec priest to shadow) or the warlock...rogue gets to come along after the instances are clear to open up any locked chests

That being said, I'm now going to level up 3 more shaman on the mage and priest accounts to allow me to run my current group or 4 shaman + paladin as needed and that's one of the best things about multiboxing I think....if we work out we need a different class we can get them up to speed a lot more quickly through boosting without having to rely on people doing it for us so it's a lot easier to try out new combinations and find what works best for the individual and their goals than someone that has to make a choice initially and then, if they find out they don't like the class, have to put up with playing what they dont like/isn't effective or spend a few months getting a new character leveled and geared to their current level.