An “evil” framework might look something like this:
It entices developers with big promises, while making huge, often unstated, demands.
It overloads developers with new concepts, until the framework steals the focus from the actual web we all work on. The concept overload creates a niche, and creates a false sense of scarcity, giving the impression that hiring the wrong type of developer will be more costly. Developers spend lots of free time practicing the evil framework to stay employable.
Job boards are flooded with ads that require experience in the evil framework. The demand is created by the high adoption rate, combined with the higher turnover from the chaos and burnout left in the evil framework’s wake. New developers count the ads and add the “evil framework” to their CV.
The evil framework would quickly dominate the job market. Developers, looking for work, study technologies that companies are hiring for. Companies can either adopt it themselves or have a significantly smaller candidate pool to choose from.
The evil framework would frequently reinvent itself to maintain market dominance, while companies bear the cost of upgrades and developers struggle to implement them. The evil framework must reinvent itself to fix the problems that it causes.
The evil framework might have a tribe of committed evangelists, who now depend on the success of the framework to find work.
The evil framework’s efficacy claims are difficult to substantiate, but once adopted, the cost of switching to something else is too high. Reasoning here being that we’ve invested too much into it, and we don’t have time to switch to anything else.
This can happen without anyone’s explicit intent. There is actually an essay on how worse software tends to dominate the market. The Rise of Worse is Better