It's Switzerland, tunnels there always have the secondary use of being usable as bunkers in a war. Also... it's Switzerland, half the country is mountains. These guys know how to build tunnels for cheap, if anyone can scale this to being cheap enough it's them.
Im concurring with you and dissenting with lom. Switzerland is very mountainous that trains laid on the surface will actually be a very very stupid proposition, with active gearing and such and with reduced cargo weight to match. Yes, they have indeed perfected trains on rugged slopes, but only because back then tunneling is a very slow and manual operation that it's not economically and technologically feasible. Lom would be right if the mountains are gentler slopes, but I think lom haven't visited the Alps and appreciate the problem. In this case, the tunnels are actually a far better and more economical solution than overground trains.
Interesting perspective. I have been to the Alps several times, and do realize how limiting it can be. That's the reason the CBT and Gotthard base Tunnel is so important and plays such a central role. The problems start there, upgrading these two massive pieces of infrastructure to support these new types of trains (also note the vendor lock in through novel systems) would be costly and probably not possible without delays for current freight.