It's interesting you point out it would be a "slippery slope" to be on.

It isn't a hard stretch to imagine in the future, you need to turn safeSearch off to see them in search results. Sometime further in the future you'll need to add some other preference or something to see them. Then, you'll need to be logged in and have a "verified" account. Then....

I think it's safe to say Google are well and truly on the slope of slipperiness.