Are there passive attenuators that don't zero volume and only offer one input ?

Not at all, if you check back through each post I have not mentioned other manufacturers product name, or personal names,  and I have also avoided,  as best I can,  stating my own. This page being the exception.

Think of other manufacturers of passives, rather than the one you refer to, and it all begins to make sense.  

Let's hope things improve, so all passive manufacturers move forward  & cater for features that make passives, the only choice. 

To refute the libel being saturated by one forum member in this thread,

Forgive me, haven't been following this thread so maybe this is explained elsewhere. But how exactly do you saturate libel? 

That is easy, just carefully read each post, and refer to your dictionary for the meaning of the word.