I'm sure, Amazon as a big business has factored in the the tax write off they will get and by the time the vehicles are in need of expensive repair and battery replacement they have gotten their value for them and tax write off is depleted.
This is far different for the people like me who do not want a vehicle that becomes a huge money pit in 10 years or so. If you do not drive a lot like me, the extra cost of the electric vehicle will not pay for itself in reduced fuel cost in 10 years.