Towpaths are part of the navigable system. Fishing is an activity in the main available only to those who are members of clubs which lease fishing rights, so an activity which has its own income and costs, just like boating. So neither would, on your logic, be funded by the taxpayer. Spending on bug hotels is peanuts in the bigger picture.
Yes I appreciate completely that the ‘other stuff’ is an integral part of what makes the canal system an enjoyable place to use, and part of the appeal for me.
All I meant was, to try and separate essential maintenance costs from total running costs.
To better try and explain what I mean; I also have a 1950’s motorbike, essential costs are petrol, oil and replacing any bits that break (or fall off and are lost), ‘other stuff’ is insurance, bike leathers, club membership etc.