You're mostly right on this. Beautiful Music was largely enjoyed by people my grandparents age. My grandparents would have been in their 40s when Beautiful Music emerged as a format.Well, for a long time, this was true. The older you were, the more likely you enjoyed softer music. Beautiful music stations were originally for the 25-54 crowd.
But it turned out, the format specifically for people born in the 1920s and 30s, not for all people aged 40 and up forever.
I would theorize that the preference for "soft music" was simply because that's what my grandparents had always known. When they were growing up, popular music wasn't distributed as recordings, it was distributed as sheet music out of the Sears catalogue. My grandparents heard heard popular when their aunt played it on piano or their dad played it on harmonica. The singers of "standards" largely performed those same songs, and did it better than Aunt Ruby and Uncle Vern.
The same wasn't true of baby boomers, who were much less interested in learning how to play piano to enjoy popular song in the "old fashioned" way. Piano sales in the US fell dramatically during the great depression, and never returned to the highs of the 1920s. Piano sales in 1950 were half of what they had been in 1925, despite a dramatically larger US population.


