That was actually reblog from Reading with a Vengeance… but, we’re also pretty sick of the whole ambitious characters are automatically evil cliche. Because, just picking someone who doesn’t want the power as your hero is a terrible idea.
There’s two simple problems with this:
First, if you don’t want a job, you’re not going to want to do it. Someone can skirt around this by invoking duty, patriotism, obligation, or whatever, but… that’s not going to make you do a good job, it’s just going to force you to do it. If you want an example of this, you only need to look at Buffy, and the absolutely terrible job she does as the Slayer.
Second, not wanting the job doesn’t mystically make you more resistant to whatever corrupting influence might come along with it. Again, I’ll cite Buffy, and her habit of bullying unpowered high school students to get her way. Not because it’s part of her job, but as a textbook abuse of power.
You can have a character who says something like, “I didn’t ask for this, but I’m going to do the best job I can, because that’s who I am, and what I believe in.” It’s a legitimate expression of the protagonist who’s genuinely the best choice for a job they don’t want. However, I’m not seeing a lot of that style of character these days.