Leave SafeSearch on by default, making users turn it off if they want smut. It's not that hard. They had no reason to change it. By turning Safesearch off I made an adult decision to allow my content to be uncensored. Filtering any results after SafeSearch is off is continued censorship of my results.
Google clearly doesn't understand that part of making a functioning search engine is delivering users the EXACT results they wanted, even if those results are a piracy torrent, porn, or a competitors product. They are sinking the ship that made this company what it is.
"But all you have to do is put in 'porn'." Great, I wonder how many of those searches are going to get flagged and sent off to the porn industry who's just aching to sue everyone they can for pirating smut. This isn't about protection, it's about sorting the searches into the content people are after. People cannot claim they accidently found adult images now, much more easy to track.