Probably most of what's been said is true. But I also think part of the problem is the sheer number of bands and artists out there these days. Back when I was a kid (Frampton's days lol), there were a dozen well known "big bands". I think back then music producers had to take chances, because they had no choice; there simply was not the "bandwagon" going on that there is today.
Now, anyone that can play 3 chords wants to form a band and make the big time. And some of them work hard to do it, approaching producers in droves, begging for a chance. The music companies can pick & choose only the most marketable.
I personally think the video era killed the music industry, anyway. It created the glam and the allure of big money and fame. Before that, it was hard working guys putting on live shows. Music was sold by sound, not sight.
Just my thoughts.
...so ever since then, I always hang on to the buckle.