Because there is no skin in the game. A C# programmer can write Java, but it might take them 3 months to be as fast as an already Java experienced programmer.

Because there is no skin in the game. A C# programmer can write Java, but it might take them 3 months to be as fast as an already Java experienced programmer. And a coder can leave at any time. There is no long termism unfortunately. So this is the equivalent of not wanting to hire someone who has only been a waiter as barstaff or vice versa, and not wanting to train them, when people are changing job every 6 months. Google can't afford to be like this, with all their systems no one else uses!