But the same systemic weakness that enables Swatting can be exploited here. Specifically that the government assumes good faith. Instead of sending a SWAT team to your house I can sign up for a DDoS in your name.
Apart from people (hopefully) not using their real names to make the ddos request, I would guess the investigation is done by a tech department rather than non specialist officers.
I don't think non technical people could pursue the investigation at all. I'm technical but not in that specialism so I'd have to do some studying just to get started.
Do you really imagine a patrol cop gets given a computer and told to 'find the suspect'? The legislators have someone else write what they put their name to, so that's not comparable.
Depends entirely on how the police reacts, but it could as well lead to them confiscating all of your computers and putting you in a jail.
Of course, swatting is worse. An on-demand terrorist attack by phone call is hard to top. But this one can be pretty bad too. Well, or maybe not, because it's not the starting evidence that makes it bad.