"4. Not Suitable for Fully Professional Productions"
Unadulterated BS
No operational definition of "fully professional" is suggested and BiaB tracks given the renown performers and other variables are assuredly pro level.
A personal example, we recently received 15,000 Spotify plays in 30 days of a BiaB based production. This was a result of our song being on a playlist of 70's major hits as the list curator thought it sounded similar. We were 1 of 4 unknowns on the list of 80 songs. And we have 27 BiaB based songs licensed. Surely a few of these curators and licensors know what they are doing!
And that's how I really feel.

Bud