I have been a cyclist for years.
Geneva has a beautiful cycling path from my home just behind the Hilton to Lausanne.
I usually did my Genève-Nyon-Genève, rolling at an average speed of 28 Kmh according to my Cyclometer, but I reached sometimes 42 Kmh on a flat gentle slope ( you can reach 70 kmh when rolling down from a hill

...
The thing is, sometimes, rolling at near 40 kmh on a bike without a bell ( road race bikes have no bells ) I had to yell a people that wandered around, or entered the cycling path without seen me coming.
Man, that was dangerous, for me and for them... Have you ever clashed with a bike rolling at 40 kmh ? I'm sure it must hurt bad.
So, I think people should think more about it. Cycling paths are for bikes and specially outside the city, for fast road bikes.
If you want to roll on them, do it but remember the bikes are prioritary and much faster than you.