One possible reason could be a major disagreement. Maybe the Avengers made a decision that Tony strongly opposed, like a dangerous mission plan that he thought was too risky. For example, if they decided to team up with a morally ambiguous character without proper precautions. Another reason might be personal issues. Tony could be going through something in his personal life that makes him want to distance himself from the group, like dealing with the stress of his identity as Iron Man being public and feeling the Avengers draw too much unwanted attention.
Perhaps in the fanfiction, Tony Stark throws out the Avengers because he feels they've become too complacent. He's always been about innovation and progress, and if he sees the others resting on their laurels, not training hard enough or keeping up with the latest technology, he might decide to cut ties. Also, there could be a betrayal within the group. If one of the Avengers did something that endangered the team or broke Tony's trust, like secretly sharing confidential information, he could lose his patience and throw them out.
In some fanfictions, Tony Stark might throw out the Avengers due to power struggles. He may feel that his leadership or ideas are constantly being undermined. For instance, if Captain America always challenges his decisions without really considering his perspective. Or it could be related to resources. If Tony is the one mainly funding the Avengers and he feels the others are misusing or taking for granted the resources he provides, he could decide to send them packing.
One reason could be that he's frustrated with the leadership or the direction the Avengers are taking in the fanfiction. He might feel his ideas are not being heard.
Tony Stark may dislike Avengers fanfiction because it can mess with the emotional core of the team. The real relationships between the Avengers are deep and complex. Fanfiction might simplify or distort these relationships. For instance, his friendship with Steve Rogers has many layers, and fanfiction could make it into something that doesn't do justice to their real bond. Also, he's a man who values his privacy to an extent. Fanfiction might delve into his personal life in ways that he doesn't appreciate, making him feel exposed and misrepresented.
It could also be due to a clash of ideologies. Tony is a scientific genius and has a very practical and sometimes self - reliant approach. If the other Avengers have a more idealistic or group - centered ideology that constantly clashes with his, he might just lose his patience and kick them out.
It could also be due to emotional turmoil. Tony has lost a lot in his life, like his parents and some of his friends. In the fanfic, if he was faced with a situation that reminded him of those losses or if he had a falling - out with a close ally like Pepper or Rhodey, the emotional shock could be so great that he collapses. He's a man who often keeps his emotions bottled up, and when they finally break through, it could have a physical manifestation like a collapse.
One possible reason could be jealousy. Maybe Tony's intelligence and wealth made some Avengers feel inferior, and over time, that festered into betrayal. For example, if Tony developed a new technology that could potentially overshadow their own abilities, they might feel threatened.
Perhaps it's due to personal relationships. He might have had a falling - out with one or more of the other Avengers. Like if there were misunderstandings or betrayals. In some fanfictions, a conflict with Steve over leadership or ideological differences could lead to Tony leaving the team.
Perhaps he leaves for personal growth. America has become a place full of painful memories for him, like the loss of friends during battles that happened on American soil. So, he decides to start anew in another place.
Maybe he doesn't fully understand his powers yet. Tony Stark is a scientific genius, but new powers might be beyond his current understanding. He could be worried that if he reveals them too soon, he won't be able to control them properly and might cause harm. So, he chooses to hide them while he studies and figures them out.
Differences in ideology can also play a part. Tony might have some views on how to handle threats or use technology that the other Avengers don't agree with. Maybe he's more willing to take risks with untested tech that could endanger the team or civilians, which would lead to resentment.
It could be a disgruntled former employee. Maybe someone who felt underappreciated by Stark Industries and decided to take revenge by kidnapping Tony. Another possibility is a new super - villain who wants to make a name for themselves by taking on Iron Man. They see kidnapping him as the perfect way to get attention.