"I BASED THE MAIN CHARACTER ON MYSELF."

I'm sure a skilled storyteller would be able to make it interesting, the problem is no skilled storyteller would actually put themselves in their own story.
Because doing that is something unskilled storytellers do.

The reason people do this is for several reasons, they can't write fictional characters well enough, they have a big ego so they can't imagine someone else being the main character (even a fictional character), and they are lazy.

Unskilled storytellers are unskilled, so any character they write won't be very good. It's like anything else. It's possible that you've played many excellent games where the dev wrote himself as the main character and you didn't even know it. Come to think of it, how do you know that you've played games where the main character is the dev? Which games are those?

I'm basing a character on myself and it's not because of my ego or I'm lazy.

Provolone is pretty much a stupid retelling of a real-life event. It's really obvious past a certain cutscene, but anyway, the protagonist, Seraphine, is pretty much me with amnesia on another body. And the other people are my friends. I don't think there's anything inherently wrong with that, but for instance, Provolone was a game I made by myself, for myself, never meant to be played by anyone else. So it's a different case than the usual "hey, look, it's me with a BFS / BFG"
But as a matter of fact, unless it's the aforementioned self-promoting situation, I'd actually encourage that! It's interesting to see your life from a new perspective, and to be able to share it is good for some people. I myself am real glad I made that game; It won't allow me to forget some things, which is especially good since I suffer from memory problems. And people whomever plays it won't really ever what's going on anyway hahaha.

Still, that's what I have to say: Do it. It's fun, and reflexive at that. Just don't be a self-promoting bitch, be cool!

I think there's two versions of this: the fantasy self-insert* and the personal story.

The purpose of the former is generally p. self-serving: you make a big, cool universe and then put yourself in it, so you can pretend like you're a cool person who can do cool things. It's not really a bad thing; I think just about anyone who's done creative stuff has done something like it. It tends to be a sign of a beginner creator, just because it's very difficult to write oneself as a compelling character in these settings, and because, from the purpose of anyone who isn't the creator (or a friend/family member), it's kind of annoying. (Because most people really aren't interested in you from the get-go, and there's rarely any character buildup.)

The latter is sometimes a little better about offering something to a player who isn't the creator or the creator's loved ones; it's usually more about sharing an experience than about aggrandizing the creator, so there's more thought put into that section of the audience. (This is not always the case, of course.)

I think the creator as character is more difficult to pull off effectively because it's harder to make it interesting and identifiable to others-- not because creators are inherently boring individuals, but because most people tend to have a lot of biases where they themselves are concerned. Flaws get ignored, things go without explanation because "Well, this is Thing I Care About, so clearly others will care as well!" or because the creator hasn't done enough thinking about themself to understand how they tick.

And, of course, there's a tendency sometimes to ignore consistency in writing because "Well, that's what I'm like IRL, so it's realistic!" Which isn't really how stories are normally supposed to work, and tends to put off one's audience.

There's probably also something to be said WRT one's audience being a little harder on obvious "THE CHARACTER IS ME!" because most of us expect to either be allowed to pretend WE'RE the main character, or to be introduced to somebody who's compelling.

(Obv. very little of this applies only to creator characters, and it's a generalization, but these are things I see popping up in a lot of media.)

* Named not for the genre but for the function

Self-inserts are fine as long as you stay away from wish fulfillment. Remember that the character your story centers around has OTHER characters. With other goals, which may compete with theirs. The hero might not always win. The villain may get away with that one item, forcing them to chase.

author=Pizza
The biggest difficulty that I find is that it's hard to mention that the character is based off of you, because people will immediately jump on your back about it and try to defame you for doing that shit. It's annoying, because it seems like we're trying to present the idea that basing characters off of real world people and events is always a bad idea or something.

Well, when like 99% of the available bits of a type of story are terrible, I can see why most people go with the assumption that any given individual story of that type is terrible.

If you're not working on a personal story, I can't see why you'd bother mentioning the character being a self-insert. Either it's obvious, in which case it doesn't bear mentioning, or it's not, in which case who gives a crap?

As an aside, I feel like there's a biiiiig distinction between "I based this on X thing" and "I was influenced by X thing." I include elements of myself in a lot of my characters (obviously, because I am stuck with my own viewpoint) but I haven't really based a character off of myself since early college. There's too many pitfalls to bother with it, and it's more interesting to have a diversity of personalities.

author=unity
And it's not like there aren't well-known writers who haven't blatantly modeled characters off of themselves or their situations. Maybe it is just the Mary Sues that I've been seeing.

Adaptation. comes to mind. Adaptation. is a film by Charlie Kaufman about Charlie Kaufman trying to write Adaptation..