I agree. He created a lot of really excellent stuff.
But, of course, all of that (like your comments) is purely subjective, personal opinion, without a single shred of objectivity.
I disagree.
There is such thing as an objective standard of craftsmanship in any craft, including the craft of being a recording artist.
In some aspects of that craft, Zappa excelled: he was innovative and had an impressive knowledge of musical theory as well as being a technical master of his instruments.
In some aspects: i.e. shaping ideas into a coherent whole - he was not. There are songs of his whose guitar solos will be considered important compositions in years to come. None of his lyrics will be, and few of his songs, as wholes, will be considered as such.
In fact, outside of his circle of devoted fans, few of his songs are even recognizable to the general public.
BTW, I don't think variety is unfocused - variety for variety's sake is.
"Peaches En Regalia" called. It wants to kill you.