Government subsidies for private businesses are almost never justified. The competing firms who do not get the same favoritism are unfairly hurt. Usually, the company getting the subsidy gets lazy and sloppy, but they are propped up by the taxpayer, thus misallocating resources.
Should the government have subsidized buggy-whip makers a century ago? A lot of good people lost their jobs as their companies went under. Today’s politicians would have saved them!