More then one character

It doesn't matter if you want to stick to one character or play with several different characters. Both are totally valid ways of approaching your character slots.

I can understand why some people would only want to work with one character. It gives the chance to focus only on one class and discover every last strength and weakness of that class in incredible detail. Being a true specialist like that can have some real advantages.

Although playing with several different characters can have its advantages too. I believe other posters in this thread have outlined many of those advantages already.

I have three characters, but play on just 1 now, because I want to get all the cool titles for him, and it feels like a waste of time to do the same stuff for multiple characters.

Maybe yes, maybe no. The flexibility you might have on said title (one of useful track) could be worth it.

Working on maxing my lightbringer on both my ele and my monk. Flexibility purposes for DOA. Something like that might actually be worth the headache of maxing it.

Yeah but like going to get Protector title and Cartographer title for every character is wasting time (yeah I hate having characters without any worthy titles =P).
Also Guardian title track is taking up so much time, there's no way I'm going to play with my other character while I could spend it doing missions on hard-mode or saving up for perfect gear for my Heroes.

I have one character of every profession, so that's 10, then 3 mules, a pre-searing character, and an extra monk for a guild event.
I like playing every profession - it makes me feel like I know the game better, knowing how every class works and having discovered its strengths and weaknesses first-hand.
Some have been played more than others, and now after a year and a half I have chosen my favourite of them all to go title-hunting on, leaving most of the rest sitting about idle, but I'm glad I tried every profession available.

I played a Warrior through all 3 campaigns, but I recently joined a PVE guild and it bothered me that whenever anybody needed help with anything, all I could offer was a tank.

Now there's nothing wrong with playing a tank, but sometimes you need versatility. There's only so much variety that rearranging your skill bar and changing your weapon can bring and it's very much worthwhile to be able to fulfill a different role.

I'm now playing a Ranger through Nightfall and it is awfully satisfying being able to kill things from afar.

I would say Warrior is probably the best profession to play if you're the leader of a party or the only human player, since you will be by definition the person running into battle, but as part of a human party there's a lot of satisfaction in letting someone else play that role.

Edit: It's also worth noting that it doesn't take THAT big an investment of time to play another character through a game. When you're going through the first time you want to explore every nook and cranny and take every quest, but after that you just breeze through.

I helped a friend to level her ranger from level 5 to 20 in a single day. It was very strenuous, but spread out over 3-5 days you could easily get a new character there.

Factions has the biggest XP rewards and therefore the quickest levelling to 20, so try starting a character there. The disadvantage is that you won't get skills as quest rewards so you may be put off your profession just because you don't have many skills to choose from. Persevere until you get to Kaineng Center, then you can buy the skills that take your fancy.

Couldn't agree more here, one of the best reasons for having main characters (besides potentially discovering another profession you might enjoy), is the ability to understand how other skills work, and then make them work for you. I myself learn by experimentation. Some people can just read over the skill list, and wack them together for a build, I need to test the waters and see how they actually work, which then gets the old brain ticking over for potential builds. And if for no other reason, sometimes its fun to take a break from your favorite, makes you more appreciative when you come back

All the people have touched on good/funny reasons for playing more than one character. So I'll look at another way of explaining why someone would want to spend time re-doing things on new characters.

Ever watch a movie more than once? A lot of people do this too. For one thing, you can pick up on little subtleties in the moviemaking technique and in the story that you overlooked the first time, or didn't understand the first time. The first time through, you sometimes are struggling just to survive. Going through another time, you can really get to appreciate something (sometimes).

P.S. You can't experience the primary attributes of the different classes with just one character.