I agree strongly. I have come across quite a few dojo pages where no lineage is given for the instructors, and in my opinion this makes it very hard to assess the dojo, short of actually going there in person. One example I found recently is this one, not too far from me:
They make wild statements about the present state of aikido, but there is no information that I can find on the site about where the teachers have trained before, or who awarded their grades.
Perhaps Tony Wagstaffe or Henry Ellis know Antony Day?
You will find similarly strongly-worded personal opinions on Henry Ellis's site, but then at least he does have a pedigree!
By the way mine is actually pretty simple: I started training in Oxford in the late 1970s, and for most of the time since then I have had only one teacher, Minoru Kanetsuka, who was originally a student of Gozo Shioda and then of Kazuo Chiba. My dan grades are all certified by Aikikai Hombu Dojo.
I know Tony Day - met him about 10 years ago at our summer school.
Believe his background is Yoshinkan.
Not my favourite ever website but I'd say Tony does not merit being on an "underqualified sensei" list.
Not a Southampton / Pompey thing going on is there?