Falsetto is a high vocal register and a tenor is high singing voice. Most tenors can’t reach falsetto. The ones that can are usually exploited in some way.
What irritates me, when I find out, is when I assume a male singer is a female singer because of his ability to sound like one. I know I’m not supposed to assume anything, but it’s difficult in a case where you only get to hear the music.
I don’t know diddle about music. I’m a consumer, not a creator. I couldn’t even get into band classes when I was in school. I could be wrong about the few things I actually know.
Late seventies and most of the eighties music was littered with rock bands, some good and some not so good. A lot of the lead singers were tenors, such as Steve Perry of Journey and Dennis DeYoung of Styx. Rock music seems suited to tenors.
I can’t comment on other genres, like country, where low singing voices seem to rule. I may be mistaken, but I don’t think anyone who sings lower than tenor can reach the falsetto register.
Both groups were popular in the seventies. To be fair to myself, the only time I heard them was when I heard them on the radio. Music videos didn’t exist back then and no one in my family watched music variety shows. Except for my father, when he was home. He liked “Hee Haw”, which featured country singers.
Russell Hitchcock of Air Supply isn’t a falsetto, but he definitely sounds feminine in some of their hit songs.