As a singer and a researcher I tend to be somewhat schizophrenic when it comes to the whole tradition of song fabrication. The researcher in me is rather annoyed at being bamboozled by people like Bert, Ewan, Baring Gould, Buchan, Scott etc because once we find some examples of what they've done then this taints all the rest of their material. (Exactly how much did they fabricate?) On the other hand another part of me (a mischievous part) actually admires what they've managed to do. Most of them had different motives. I think Baring Gould's main motive for getting one over on Child was his contempt for what he saw as pompous authority, and I can empathise with this.
Bert obviously couldn't resist letting his own creative juices loose on the songs.