And we used rocks as weapons before we used them for building. (Ignoring naturally forming caves).

We know media technology is led by the porn industry. Maybe physical technology is led by the weapons industry.

Ironic, because weapons industry has a lot of incentives to stop this development.

I think that's probably better phrased as, "the existing weapons industry has a lot of incentives to stop this development". Just because someone like defense distributed isn't an established arms manufacturer doesn't mean they aren't "in the industry". Same goes for other startups. The "payment industry" seems to have been greatly affected by an upstart named paypal. The "finance industry" probably doesn't like kickstarter very much. etc.