I don't really understand the dismount signs here (and haven't seen anyone, including me, bothering with them).
It would be different if the pavement was genuinely narrow, or even if it was busy, but in fact it's still wider than all of the canal towpath and so far I haven't gone under at the same time as anyone else.
Unless we want to see all of the towpath marked as dismount-only, there has to be some push back on stuff like this.
In a true Edinburgh shoot your own leg off fashion, the only really narrow bit has been produced by the people who put up the "caution narrow" sign, taking up about 60% of the width of the path.
(I believe this may even be genuine irony?)
Edit: I haven't seen anyone cycling on the other side, but I suppose if people see a giant red dismount sign, they're possibly interpreting that as the path being closed, hence using the other side. I love unintended consequences like this.