The world of theatre is a strange place, not only due to its eccentric actors, to its "modern plays", nor to its abnormal schedules, but also because it is a place to express yourself, to release those emotions that you've bottled up for years... and then get someone to perform them on stage?
Many people release sadness of a particularly bad break-up through a painting, for example, or they will vent their anger and frustration of their world or the world around them in a form of a poem or a short story. But the strangest, almost funniest, way to release emotions, especially personal emotions of a particular circumstance or situation, is writing a play about it. I shouldn't really say strange because I do think that writing about something that has bothered you or is still bothering you is a good antidote; it can put your situation in perspective. I suppose the real funny thing about this is when you pen something hurtful that happened to you in your past, and then you spend weeks or months perfecting this very personal script, just so you can see it acted out in front of you! Yes, instead of burying these emotions deep within your wounded soul, you intentionally thrust these sharded feelings up on stage, for everyone to see, as well as yourself, so you have the opportunity to relive this horribly negative experience (that you likely never wanted to go through again) many times on stage!
Of course, not every dramatist has the desire to write about their darkest times, nor do many of them choose to write about something so close to home. It is true, however, that the majority of playwrights to tend to slip in at least something personal (such as a specific character or a political view they may have) into their scripts. It's very tempting to add something of youreslf into the script because it is always neat to watch something that has something of you in it. It's like your very own private joke.
So, is playwriting only for the strong and the bold? Not at all; people write anything from a milkman to octopus' to the country of Latvia. For some, it's just another way to get those artsy fartsy I'm-so-filled-with-emotions out. It is just peculiar that seeing your problem acted out on stage can be therapeutic, but I suppose it could be the interpretation of your play that you are interested in. Perhaps it helps you realize that others are in the same boat, or even, it helps you find a solution or a way to move on.
At the auditions yesterday, I had the opportunity to read almost the entire script of one of the plays. It is student written. I was shocked at the content of the script because I know the playwright, and I could never see him writing something like that. He is witty and funny, sometimes quiet, and he is a brilliantly hilarious actor. I just did not see him writing about a love triangle. Although, as Andrea pointed out, maybe he's just writing about something that happened to him. Makes sense -- even the witty and the funny get into difficult situations.
In a way, that reminds me of how interesting it is to read something for the first time of someone you already know. Sometimes, their writing comes to you as a complete surprise. You would have never guessed that they write that way! It makes you think about them in a slightly different way; you have now pierced into their life as a writer. I believe that someone's writing is a critical part about them, especially if they are one to write articles, music, or even a weblog.
Of course, something that is potentially even more interesting is meeting someone after having read and followed their blog religiously. Interesting, yes, but not necessarily pleasant.