Its pretty much the same reason why most people buy houses that are already built and renovated vs. building it themselves from a single empty plot of land. It

Its pretty much the same reason why most people buy houses that are already built and renovated vs. building it themselves from a single empty plot of land. It's far more of a sure thing that you can move into immediately vs. possibly not move into at all. You can choose an potential employee to train who may not 'just get it' for a cost far higher than hiring the experienced guy would cost. It's like building a house with cost overruns that your construction loan won't cover anymore and you cant get any more money. You end with a huge useless debt that YOU have to pay now and a useless half-finished house that most people don't want to buy. Also when you train employees, you get these retention contracts that can create a perverse incentive for and employee to take advantage of or a deal as an employee that you wouldn't want to take, because you'd have to pay for a training cost subject to the whims of an employer firing you.