Johnston began recording John Lennon- and Beatles-inspired music in the late 1970s on a $59 Sanyo monaural Boombox, singing and playing guitar, piano, and chord organ.
And especially to Smith:
He cited his influences while growing up as Bob Dylan, KISS, The Clash, Elvis Costello, Hank Williams, but most importantly The Beatles. Smith continued to be a dedicated fan of The Beatles (as well as their solo projects) and once noted that he had been listening to them frequently since he was about "four years old."
Note that of the six "artists" cited, half of the them are British. Continuing:
In 1998, Smith recorded and contributed a cover version of the Beatles song "Because" to the American Beauty soundtrack, which can be heard during the closing credits of the film. Although this was the only Beatles song that Smith ever officially released, he was known to have recorded at least one other ("Revolution", during the sessions for XO), and played many during his live concerts. Among the songs he is known to have played during concerts are "Blackbird", "Yer Blues", "I Me Mine", "For No One", "Something", "I'm So Tired", "Long, Long, Long", and "I'm Only Sleeping". He also played from the Beatles members' solo careers including the John Lennon song "Jealous Guy", and the George Harrison songs "Give Me Love", "My Sweet Lord", and "Isn't it a Pity?". Smith was also rumored to have recorded a version of "Hey Jude" for the 2001 Wes Anderson film The Royal Tenenbaums to be played during the opening scenes, but the song never materialized.
It would seem that the band that you laughingly label as non-artists had a profound impact on those tortured "real" artists you respect.
Not to mention - Johnston and Smith owe an awful lot to the genres of punk and synth music, which have their origins in the UK.
It is fine for you to have your personal tastes, and to find artists that touch you personally and favor them - that is what everyone does. But to essentially make the claim that only mentally ill Americans have the capacity to become "real" artists, because those happen to be the artists you favor, is patently absurd.
When you claim that the Red Hot Chili Peppers are innovative artists worthy of respect, and then deny all other artists from the Sex Pistols to Bjork, it becomes clear that you are wrapped up in your own little world. Hopefully not quite in the same way Johnston and Smith are/were.