What is a unit of "regulation"? I can pack five thousand onerous rules into one document and eliminate two documents that contain guidance with very minor impact. Is that a net gain?

Next time you write a line of code, you have to delete two others.

What would happen if we applied this for 4 years on an existing codebase, such as the Linux Kernel?

People would fix the low hanging fruit and leave the hard/hairy parts that need work the most.

True - but then eventually, everyone would have to focus on the hard/hairy parts, no?

Yup. That doesn't mean that it's not worth taking care of the easy bits first.

Most likely support for obscure devices would disappear.

To be fair, that's already starting to happen[0]. do you think it would happen faster than it is today?

0. http://www.phoronix.com/scan.php?page=news_item&px=MTI0OTg

And in this way you end up with 0 regulations, which I assume we are supposed to consider a feature, not a bug?

One regulation, at least you'd still have that.

It's nonsense. Measure regulatory burden by number of rules is absolutely arbitrary.