Fuel lines - Inside or outside of frame?

[lukemillar]

Here is a new one:

My 03 FSE 400 has started leaking fuel and I have traced it to a hole in the fuel line. Basically these lines run from the fuel pump, outside of the frame and to the injector. Where the line goes past the frame, it has rubbed against the plastic tank covers and worn through. The RHS line is showing the same wear, though hasn't started leaking yet

I did a quick search, but couldn't find any similar threads. Should these lines run inside the frame rather than outside? It seems pretty vulnerable to have this setup. I've ordered replacement lines, but I'm wondering if it is just bad design or the old ones have been installed in correctly (they have been like this since I bought the bike)

Thanks
Luke