In some countries where there are avaliable jobs, we have people working on 1, 2, 3 jobs so for such a person he already have an alternative and can easily switch for a better offer no problem.
What is a problem is when you quite your job, without any alternative, i mean you enrolled yourself into the unemployed academy, also is important to develop some skills amd training, that way when youare out of job, you have something to fall back to.
Ops can you include a link to your quote as a form of reference.
Quitting your job without a replacement has to be the most dumbest thing that anyone can ever do. Before trying to switch to a new job you must make sure that everything is already in place and you are starting immediately when you quit that particular job. This is what a lot of people don't understand, after making this mistake they end up becoming jobless because they did not play their cards right