Well, I just read most of that article and I think its fundamentally correct. It seems your referring to being realistic as being negative.
Alot of the locks are stiff and heavy. There is some grot. Blah blah.
We've done most of the GU in the last few years, and last year did the bit down to Brentford.
Dont get me wrong, me and the missus enjoyed it, neigh, loved all of it..!! There was only the two of us and we did way over 20 locks a day down to Brentford, we've done leicester a couple of times and loved it both times, and we've done Birmingham, yes its depressing...!!! I love looking at the brickwork of the buildings, seeing the dereliction, and imagining what it must of been like at the time. However, can you imagine what some of the more shall we say sensitive holiday maker folk think of all that black lifeless water, used shringes and nodders on the bank, bin bags under bridges.
One women we met last year (with her completely useless husband) in a hire boat, and others we met on their first hire boat trip would have found that article a useful and enlightening read. Admittedly there's some scare mongering going on about certain areas but some of the idealistic softies that hire these boats need a bit of that IMO.