This is a false statement.
Without getting into things that aren't talked about online, I assure you that commercial imagery is regularly used in .gov/.mil settings for a variety of purposes. This includes gap-filling (both geographically and historically), the ability to disseminate product widely without sanitization, etc. There's nothing insignificant about its use.
For MDA specifically, though, we cracked that nut and can downgrade to the point we're just giving out pngs with no evidence of where they came from.
Proliferation is huge. I can buy a high-resolution satellite photo of my neighbor's property every day if I feel like spending the money. That's something that wouldn't have been available at any cost a decade or two ago.