If Semmelweis’ s theories were correct, it would have meant that many deaths of their patients would have been easily avoidable. So those other doctors could either ridicule the theory and continue living + practicing in ignorance, or accept the theory and also accept that they had (unknowingly) caused the deaths of many of their patients.

I’m not surprised that they chose the route of ridicule. I’m also not surprised that 20 or 30 years later, when the assistants of the old doctors had become the new generation of doctors, that the theory was then more easily accepted.