How to recover your horse from the canal

I sometimes forget the tow path was for towing boats with horses. I have a favourite walk from my cottage down into the valley, over the river Churnet, across the railway lines and then over the canal... A lovely secluded walk  - I did a full walk blog here  - click me 

I have passed this feature many times now and not given it a second thought  - other than it seemed to be a nice place for the fish fry to hide in away from the predators.

Looking at photo 2 above you can see the 'steps' and ramp to aid a climb out which I have to presume was for the horse should it fall in. So therein lies my question - if there is one here - in a remote part of a lovely rural canal, why do I not see more of them on say the Shroppie or the S&W - or do I happily cruise on by no seeing what is obvious as I have done many times walking past this feature.

It also begs the question how did the boaters get their horses out of the canal (assuming they did occasionally fall in) where no such feature was present?