By itself, there's nothing wrong with government buying services from private companies - in fact, it's inevitable, unless the whole economy is controlled by the government, certain services will have to be bought on private markets. It is when the unique power position of the government is leveraged to give certain companies unearned advantage, and the government acts not as mere consumer among others, even if with deep pockets and special needs, but seeks to promote some companies at the cost of suppressing others, is where the trouble lies.