My ‘new’ Trek has brake hose routing under the downtube.

Anyone flicked up a rock and damaged a hose?

Nope. Never happened to me

Nope, had it on 2 bikes now (Enduro and Airdrop) both have been abused and taken dents to down tube but brakes remained fine.

Rather a damaged hose than a damaged down tube !

^ My thought exactly and hose is pretty tough

Had a rock flick up and take a hose out on my stumpy evo a few years back same happened to my mates enduro at the mega last year but it wasn’t a regular thing and wouldn’t put me off

Never had an issue. However, my Trek Crockett frame came designed for either a hydraulic hose underneath the downtube or a cable through the frame. I drilled the cable stops and ran a hydraulic hose through the frame as it looked nicer.