The problem for regulating software development is still who gets to formally determine who the "good" people are. This kind of thing should clearly be objective and evidence-based but what useful evidence do we have available?
In physical engineering disciplines there are often clearly evident problems if something was built without being adequately specified by the responsible engineers. In a disastrous case a bridge might literally fall down but you're also going to see that a bridge wasn't designed properly if it's distorting in ways it shouldn't under loads that it should be able to support. There are lots of experienced engineers who have proven records specifying buildings or planes or ships that need to not break using established and peer reviewed techniques.
In software we can all agree catastrophic failures that result in loss of life or half the Internet going down are obviously bad. For something controlling a life-saving medical device or the launch authorisation system for the nuclear missiles we can probably all agree that the answer to what quality level we want in the software is "the best quality we can achieve". But those systems have unusually serious consequences if anything ever goes wrong and probably also very high development budgets that can justify such an extreme position on quality. In general we don't have clearly defined levels of software where different trade-offs between cost and risks and other factors might be considered reasonable and acceptable. Nor do we have well tested and universally accepted standards for how to reliably achieve a specified quality level.
There is zero useful evidence because there is no one to collect it.
The Institution of Civil Engineers was founded in 1818, after decades of random civil engineering societies in Britain doing the exact same thing we are now (running around like chickens with their heads cut off). It wasn't until after the ICE's Royal Charter a decade later that civil engineering began to get really systematized into the "real engineering" we know today and that charter effectively established them as a regulatory body that allowed that to happen.
I'm not sure that is entirely true. There have certainly been a few people who have attempted to study what did or didn't work in industrial settings - either pure academics or people working in industrial research labs. But I agree that currently we have nowhere near enough data to form robust conclusions about almost anything in this field and I think this is the strongest argument that the industry is not ready for any kind of licensing and regulation regime.