Smurfobia was just the unique JW strain of the 80s' "Satanic Panic".
Personally, I thought it was stupid even back then*...
...older dyed-in-the-wool Dubs were completely freaked out about it (along with Dungeons and Dragons), and frankly, I was relieved when both crazes petered out, just so they'd finally shut up about it.
"Backmasking", too...
...CDs became common, and the panicmongers barely had a leg to stand on, 'cause you couldn't play 'em backwards (even if you wanted to).
...
* I always suspected the anecdotes about "demonized" Smurf dolls started out as a deliberate bullshit story some young JW prankster started just to see how many dumbass loyalists would actually believe it.