By all accounts, the process of selling Twitter is well under way. The company has hired an investment advisor and is expected to start receiving bids later this week from a group of interested parties that reportedly includes Google, Salesforce and Disney.

As it does in almost every case in which a once-promising technology company is about to be acquired, Twitter’s likely sale represents both a success and a failure.

It’s a success in the sense that the company managed to build a service valued at $17 billion that is used by more than 300 million people, and has played a role in everything from the Arab Spring to the rise of Donald Trump and the chaos that is the U.S. presidential race.

But Twitter’s TWTR story is also a story of failure—a failure to capitalize on that early promise and a failure to properly manage the company’s growth or strategy.

Facebook CEO Mark Zuckerberg once famously described Twitter as “a clown car that drove into a gold mine,” and for much of its history the clownish aspects of the company have been far more obvious than the golden parts. In a very real sense, it’s almost a miracle that the service still exists at all considering all the turmoil and upheaval in the executive suite.

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To take just one example, Twitter had six different people in charge of the product in as many years, which helps explain why it has gone through so many back-and-forth iterations and false starts.

Twitter CEO Jack Dorsey’s fate has been intertwined with that of the company he co-founded from the moment the service was born in 2006 (in classic Twitter fashion, none of the co-founders can agree on whose idea it was, or what it was originally designed to do).

Dorsey started out as an evangelist for the idea of Twitter, then was forced out by his boss, Evan Williams, who became CEO. Williams himself was later forced out, and Dorsey returned as product visionary. When CEO Dick Costolo left, the board decided—against the advice of many—to make Dorsey CEO, even though he was already CEO of mobile-payment company Square.

To a large extent, then, the likely sale of Twitter a year after he returned as CEO represents a personal failure for Dorsey. He was supposed to fix the company and get it back on track, and he has not.

According to a recent Bloomberg report, in fact, much of the company’s strategic focus over the past year—streaming live video for events such as the NFL and the election debates—has actually come from chief financial officer Anthony Noto.

The pressure to sell the company, meanwhile, has come from none other than Evan Williams, as well as from early investors such as Chris Sacca, who said in a recent interview that he had hoped Williams would be more involved with the product and that he has lost patience with Dorsey.

One could argue, as Vanity Fair writer Nick Bilton did in a recent piece, that it was unreasonable to think that even Dorsey could rescue Twitter from its fate.

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As powerful as the service is when it comes to allowing users to break news, the business side of the company has never been on terribly firm ground, and that landscape has since become even more unstable as Twitter’s growth has plateaued. Both in terms of users and engagement, the company looks significantly less appealing than either Facebook or newer rivals such as Snapchat.

And now it falls to someone else to figure out how to fix Twitter, or at least figure out how to capitalize on its strengths and minimize its weaknesses. The big problem for any acquirer is that those two things are inextricably linked, and you can’t change one without altering the other.

The same features that allow Twitter to become a powerful tool for activism and social justice in cases like Black Lives Matter can also turn it into a megaphone for harassment and hate. Twitter has been trying to figure out how to amplify the former and curtail the latter for more than two years now, but it has made little progress.

And what happens after an acquisition? Salesforce may be able to use its corporate connections to make Twitter more useful to a broader range of people. Or Google could integrate it into its massive ad system and find synergies that make sense. Disney might be able to help Twitter capitalize on its live video and sports features and find new partners.

Whoever takes on that challenge will be buying what has to be one of the most perplexing technology companies in modern history, a service that is arguably both a huge success and a massive failure at the same time. And that is not an easy thing to fix. Just ask Jack Dorsey.