As others have said, someone entering the US on a tourist or other nonimmigrant visa, then marrying a US citizen, is inherently committing fraud because the marriage demonstrates intent to stay. In the past, the US was nice about it and let people apply to adjust their status without leaving. This loophole is now closed.
Are you saying that in such cases, the US rules here are and should be that the married couple should live apart for years due to the bylaws of the USCIS?
As I said, this is inherently a violation of the commitment the visitor made when entering the US on a non-immigrant visa, as much as (say) exceeding the limit on the hours per week an international student can work.
>Are you saying that in such cases, the US rules here are and should be that the married couple should live apart for years due to the bylaws of the USCIS?
First, this is what the law has always said; there is a reason why non-immigrant, immigrant, and dual-intent visa types exist. The USCIS memo reiterates this, while clarifying that the agency will no longer grant the contrary-to-the-law leeway it has heretofore done regarding non-immigrant, non dual-intent visas.
Second, the alternatives of 1) K-1 (fiancee) visa or 2) CR-1 (spousal) visa exist, and have always been the intended means for the person you mentioned in your situation.
The leeway meant that pretty much anyone, including illegal aliens, could obtain a green card (and be exempt from removal during the application process) by marrying a US citizen.
A US citizen is free to marry anyone, regardless of citizenship. There is no automatic guarantee, however, that the couple can both live in the US.