Wesley - "Nashville Skyline" (1968) was a departure into country music that was meant to throw a curve at his audience's expectations, but it wasn't a "bad album" as such. "Self-Portrait" (1970?) was an album deliberately concocted to demolish the "Voice of a generation" icon worship that was occurring around Bob. He figured his fans would mostly hate it, and hopefully would go away...

That said, there is still some good stuff on Self-Portrait...and there's some very poor stuff too. It's an odd hodge-podge of material.

"John Wesley Harding" (1967) was another major departure in style (after Blonde on Blonde), but it was a very good album.

So to answer your question...I think he deliberately calculated "Self-Portrait" to be received as a "bad album" and get people off his back.

Those who have the most stringent requirements and rigid expectations about their heroes (or goats) are the ones most likely to be disappointed...