I received an offer from McKinsey last Friday to start in September, their recruitment process was significantly delayed (their issue) and I had to accept a job offer fast due to personal reasons so I accepted another company offer to start next week.ย
Now McKinsey is threating me to rescind their offer if I start working for this other firm even for just 1 day even if I explained them that I needed a plan B but they were my first choice and I would quit the other one to join them. They are not competitors, it`s a totally different firm and might be their client but that`s the only thing they could care about.ย
I don`t understand this request for me to be unemployed before joining them?