I believe people that would thrive in that environment would already be working as contractors or founders or at least in an industry where compensation is strongly tied to recent KPI's like sales or finance.
Things might be different if everyone was doing it like you say, but as it is right now there's a lot of work and friction involved with changing jobs. Getting hired is an ordeal during which you're not getting paid. If someone receives an offer from A with which they can be 90% sure that they'll have the position in a year or two if they want it still, or from B where they will most likely have no job again next week, why the hell would they ever choose B? Let alone common scenarios that come with job change such as moving a family, buying a house in a different city, intentionally leaving a specific position elsewhere to gamble on this one, etc.
I'm almost certain you'd be signing yourself up to employ the worst the labour pool has to offer, which is going to suck no matter how quickly you fire because you're still going to have to be on boarding them.
Things might be different if everyone was doing it like you say, but as it is right now there's a lot of work and friction involved with changing jobs. Getting hired is an ordeal during which you're not getting paid. If someone receives an offer from A with which they can be 90% sure that they'll have the position in a year or two if they want it still, or from B where they will most likely have no job again next week, why the hell would they ever choose B? Let alone common scenarios that come with job change such as moving a family, buying a house in a different city, intentionally leaving a specific position elsewhere to gamble on this one, etc.
I'm almost certain you'd be signing yourself up to employ the worst the labour pool has to offer, which is going to suck no matter how quickly you fire because you're still going to have to be on boarding them.