FWIW I am an immigrant myself (in Australia) and I am in favour of strict regulation. Skilled migration schemes should bring in skilled people, I've seen many people migrating on a skilled visa only to end up making a living as taxi drivers.
My previous comment is more related to the fact that some migrants that follow the rules, may suffer from the fact that other migrants don't - for example at first my wife could not join me in Australia, because she comes from a country which had a high number of irregular applications in the past and for this reason that country is now considered "higher risk".
For this reason, many migrants are actually in favour of stricter regulations.
This fact is often not evident if you're not a migrant yourself, that's why I wanted to bring it up.
If so, then maybe they shouldn't have been issued "skilled worker" visa in the first place. Part of the visa process should be verification that a person really has the credentials to work in the profession they declare on their application.
Of course there also could be a process to get that accreditation without coming to the country. Something like bar exams for lawyers could be held in US embassies around the world, or online.