This happened because the hand picked candidate had no chance! Then we had two, but no vote because both would likely be acceptable to the conservatives in congress and that will not happen while the establishment still breathes!
In fairness, a delay of a week or so would seem to be in order—McCarthy dropping out does change things. Other people might run. Even if others don’t, people who were planning on voting for McCarthy finding out at the last minute that they he is not an option and having to vote between one of the two remaining candidates would be placed in an unfair situation.