Generally mainstream press in the States is focused on American artists. Just a business.
This isn’t really true at all*, but to add context:
Maiden was a fixture on MTV, they were actually one of the first videos shown on the original MTV broadcast. When Headbangers Ball started Maiden were heavily featured there as well.
Maiden made an aggressive play for the states early on touring as early as 1981 culminating in multiple trips to the USA for the World Slavery Tour commemorated on Live After Death (mostly recorded in the USA).
While metal music in general was largely ignored by taste making magazines like Rolling Stone, the guitar playing trade magazines was a bastion for Metal and was where Maiden received a lot of their press in the 80s.
The idea that Maiden were ignored by the mainstream in the US is a myth created by their PR machine. It’s easily debunked by plenty of historic records as well as first hand accounts by Americans, particularly those who were following them in the 80s.
*Going off topic here, but America has a long history of covering groups outside of the USA. In the 60s, 80s, and 90s there were infamous waves of British artists championed by mainstream music press including The Beatles, Rolling Stones, David Bowie, Phil Collins/Genesis, Peter Gabriel, Radiohead Oasis, countless others. Also Brazilian and Indian music in the 60s. Even now KPop music is a dominant mainstream music in the USA, with many retailers carrying
only physical media from kpop artists. “Import music” is a huge part of the American mainstream.