I don't know how it was achieved, but I would guess it was to choose a number that helps subsidize the majority of people without sounding unfair to anyone. If you go to 30k then you exclude most of the offerings, as the cost of EVs is currently still high.
Now 60k is a number that includes common middle cars (A4, C-Class, BMW3) or even the next line depending on the configuration. These are cars that are already expensive for the vast amount of the population, but still common enough that you should not reject the offer from those buyers. Especially since this is a price number where you still see an amount of private purchasers.
Everything above is mostly purchased by companies or by some very rich people. It does not make sense for the government to throw tax money at them.
Now 60k is a number that includes common middle cars (A4, C-Class, BMW3) or even the next line depending on the configuration. These are cars that are already expensive for the vast amount of the population, but still common enough that you should not reject the offer from those buyers. Especially since this is a price number where you still see an amount of private purchasers.
Everything above is mostly purchased by companies or by some very rich people. It does not make sense for the government to throw tax money at them.